Implemented experimental Script Console for debugging with editor in the diag ui.

distribution/debian/rules

@@ -3,7 +3,7 @@
 # Uncomment this to turn on verbose mode.
 #export DH_VERBOSE=1
 
-EXCLUDE_MODULEREFS = crypt32 httpapi __Internal ole32.dll libmonosgen-2.0
+EXCLUDE_MODULEREFS = crypt32 httpapi __Internal ole32.dll libmonosgen-2.0 clr mscorlib mscoree.dll Microsoft.DiaSymReader.Native.x86.dll Microsoft.DiaSymReader.Native.amd64.dll
 
 %:
 	dh $@ --with=systemd --with=cli

frontend/gulp/webpack.js

@@ -119,6 +119,11 @@ const config = {
     rules: [
       {
         test: /\.worker\.js$/,
+        issuer: {
+          // monaco-editor includes the editor.worker.js in other language workers,
+          // don't use worker-loader in that case
+          exclude: /monaco-editor/
+        },
         use: {
           loader: 'worker-loader',
           options: {

frontend/src/App/AppRoutes.js

@@ -33,6 +33,7 @@ import BackupsConnector from 'System/Backup/BackupsConnector';
 import UpdatesConnector from 'System/Updates/UpdatesConnector';
 import LogsTableConnector from 'System/Events/LogsTableConnector';
 import Logs from 'System/Logs/Logs';
+import Diagnostic from 'Diagnostic/Diagnostic';
 
 function AppRoutes(props) {
   const {
@@ -229,6 +230,15 @@ function AppRoutes(props) {
         component={Logs}
       />
 
+      {/*
+        Diagnostics
+      */}
+
+      <Route
+        path="/diag"
+        component={Diagnostic}
+      />
+
       {/*
         Not Found
       */}

frontend/src/Components/Page/Sidebar/PageSidebar.js

@@ -165,6 +165,23 @@ const links = [
         to: '/system/logs/files'
       }
     ]
+  },
+
+  {
+    iconName: icons.DEBUG,
+    hidden: true,
+    title: 'Diagnostics',
+    to: '/diag/status',
+    children: [
+      {
+        title: 'Status',
+        to: '/diag/status'
+      },
+      {
+        title: 'Script Console',
+        to: '/diag/script'
+      }
+    ]
   }
 ];
 
@@ -473,6 +490,10 @@ class PageSidebar extends Component {
                 const isActiveParent = activeParent === link.to;
                 const hasActiveChild = hasActiveChildLink(link, pathname);
 
+                if (link.hidden && !isActiveParent && !hasActiveChild) {
+                  return null;
+                }
+
                 return (
                   <PageSidebarItem
                     key={link.to}

frontend/src/Components/Page/Toolbar/PageToolbarButton.js

@@ -41,6 +41,7 @@ function PageToolbarButton(props) {
 }
 
 PageToolbarButton.propTypes = {
+  ...Link.propTypes,
   label: PropTypes.string.isRequired,
   iconName: PropTypes.object.isRequired,
   spinningName: PropTypes.object,

frontend/src/Diagnostic/Diagnostic.js

@@ -0,0 +1,44 @@
+import React, { Component } from 'react';
+import { Route, Redirect } from 'react-router-dom';
+import getPathWithUrlBase from 'Utilities/getPathWithUrlBase';
+import Switch from 'Components/Router/Switch';
+import StatusConnector from './Status/StatusConnector';
+import ScriptConnector from './Script/ScriptConnector';
+
+class Diagnostic extends Component {
+
+  //
+  // Render
+
+  render() {
+    return (
+      <Switch>
+        <Route
+          exact={true}
+          path="/diag/status"
+          component={StatusConnector}
+        />
+        <Route
+          exact={true}
+          path="/diag/script"
+          component={ScriptConnector}
+        />
+
+        {/* Redirect root to status */}
+        <Route
+          exact={true}
+          path="/diag"
+          render={() => {
+            return (
+              <Redirect
+                to={getPathWithUrlBase('/diag/status')}
+              />
+            );
+          }}
+        />
+      </Switch>
+    );
+  }
+}
+
+export default Diagnostic;

frontend/src/Diagnostic/Script/MonacoEditor.js

@@ -0,0 +1,82 @@
+import ReactMonacoEditor from 'react-monaco-editor';
+import shallowEqual from 'shallowequal';
+
+// All editor features -> 7.56 MiB
+// import 'monaco-editor/esm/vs/editor/editor.all';
+
+// Only the needed editor features -> 6.88 MiB
+import 'monaco-editor/esm/vs/editor/browser/controller/coreCommands';
+import 'monaco-editor/esm/vs/editor/browser/widget/codeEditorWidget';
+// import 'monaco-editor/esm/vs/editor/browser/widget/diffEditorWidget';
+// import 'monaco-editor/esm/vs/editor/browser/widget/diffNavigator';
+import 'monaco-editor/esm/vs/editor/contrib/bracketMatching/bracketMatching';
+import 'monaco-editor/esm/vs/editor/contrib/caretOperations/caretOperations';
+import 'monaco-editor/esm/vs/editor/contrib/caretOperations/transpose';
+// import 'monaco-editor/esm/vs/editor/contrib/clipboard/clipboard';
+// import 'monaco-editor/esm/vs/editor/contrib/codeAction/codeActionContributions';
+// import 'monaco-editor/esm/vs/editor/contrib/codelens/codelensController';
+// import 'monaco-editor/esm/vs/editor/contrib/colorPicker/colorDetector';
+import 'monaco-editor/esm/vs/editor/contrib/comment/comment';
+import 'monaco-editor/esm/vs/editor/contrib/contextmenu/contextmenu';
+import 'monaco-editor/esm/vs/editor/contrib/cursorUndo/cursorUndo';
+import 'monaco-editor/esm/vs/editor/contrib/dnd/dnd';
+import 'monaco-editor/esm/vs/editor/contrib/find/findController';
+import 'monaco-editor/esm/vs/editor/contrib/folding/folding';
+import 'monaco-editor/esm/vs/editor/contrib/fontZoom/fontZoom';
+// import 'monaco-editor/esm/vs/editor/contrib/format/formatActions';
+// import 'monaco-editor/esm/vs/editor/contrib/goToDefinition/goToDefinitionCommands';
+// import 'monaco-editor/esm/vs/editor/contrib/goToDefinition/goToDefinitionMouse';
+// import 'monaco-editor/esm/vs/editor/contrib/gotoError/gotoError';
+import 'monaco-editor/esm/vs/editor/contrib/hover/hover';
+import 'monaco-editor/esm/vs/editor/contrib/inPlaceReplace/inPlaceReplace';
+import 'monaco-editor/esm/vs/editor/contrib/linesOperations/linesOperations';
+// import 'monaco-editor/esm/vs/editor/contrib/links/links';
+import 'monaco-editor/esm/vs/editor/contrib/multicursor/multicursor';
+// import 'monaco-editor/esm/vs/editor/contrib/parameterHints/parameterHints';
+// import 'monaco-editor/esm/vs/editor/contrib/referenceSearch/referenceSearch';
+import 'monaco-editor/esm/vs/editor/contrib/rename/rename';
+import 'monaco-editor/esm/vs/editor/contrib/smartSelect/smartSelect';
+// import 'monaco-editor/esm/vs/editor/contrib/snippet/snippetController2';
+// import 'monaco-editor/esm/vs/editor/contrib/suggest/suggestController';
+// import 'monaco-editor/esm/vs/editor/contrib/tokenization/tokenization';
+// import 'monaco-editor/esm/vs/editor/contrib/toggleTabFocusMode/toggleTabFocusMode';
+import 'monaco-editor/esm/vs/editor/contrib/wordHighlighter/wordHighlighter';
+import 'monaco-editor/esm/vs/editor/contrib/wordOperations/wordOperations';
+import 'monaco-editor/esm/vs/editor/contrib/wordPartOperations/wordPartOperations';
+
+// csharp&json language
+import 'monaco-editor/esm/vs/basic-languages/csharp/csharp';
+import 'monaco-editor/esm/vs/basic-languages/csharp/csharp.contribution';
+import 'monaco-editor/esm/vs/language/json/monaco.contribution';
+import 'monaco-editor/esm/vs/language/json/jsonWorker';
+import 'monaco-editor/esm/vs/language/json/jsonMode';
+
+// Create a WebWorker from a blob rather than an url
+import * as EditorWorker from 'monaco-editor/esm/vs/editor/editor.worker';
+import * as JsonWorker from 'monaco-editor/esm/vs/language/json/json.worker';
+
+self.MonacoEnvironment = {
+  getWorker: (moduleId, label) => {
+    if (label === 'editorWorkerService') {
+      return new EditorWorker();
+    }
+    if (label === 'json') {
+      return new JsonWorker();
+    }
+    return null;
+  }
+};
+
+class MonacoEditor extends ReactMonacoEditor {
+
+  // ReactMonacoEditor should've been PureComponent
+  shouldComponentUpdate(nextProps, nextState) {
+    if (!shallowEqual(this.props, nextProps)) {
+      return true;
+    }
+
+    return false;
+  }
+}
+
+export default MonacoEditor;

frontend/src/Diagnostic/Script/ScriptConnector.js

@@ -0,0 +1,93 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import { connect } from 'react-redux';
+import { createSelector } from 'reselect';
+import { fetchStatus, updateScript, validateScript, executeScript } from 'Store/Actions/diagnosticActions';
+import ScriptConsole from './ScriptConsole';
+import LoadingIndicator from 'Components/Loading/LoadingIndicator';
+import Alert from 'Components/Alert';
+import { kinds } from 'Helpers/Props';
+import PageContent from 'Components/Page/PageContent';
+
+function createMapStateToProps() {
+  return createSelector(
+    (state) => state.diagnostic,
+    (diag) => {
+      return {
+        isStatusPopulated: diag.status.isPopulated,
+        isScriptConsoleEnabled: diag.status.item.scriptConsoleEnabled,
+        isExecuting: diag.script.isExecuting || false,
+        isDebugging: diag.script.isDebugging || false,
+        isValidating: diag.script.isValidating,
+        code: diag.script.code,
+        result: diag.script.result,
+        validation: diag.script.validation,
+        error: diag.script.error
+      };
+    }
+  );
+}
+
+const mapDispatchToProps = {
+  fetchStatus,
+  updateScript,
+  validateScript,
+  executeScript
+};
+
+class ScriptConnector extends Component {
+
+  //
+  // Lifecycle
+
+  componentDidMount() {
+    if (!this.props.isStatusPopulated) {
+      this.props.fetchStatus();
+    }
+  }
+
+  //
+  // Render
+
+  render() {
+    if (!this.props.isStatusPopulated) {
+      return (
+        <PageContent>
+          <LoadingIndicator />
+        </PageContent>
+      );
+    } else if (!this.props.isScriptConsoleEnabled) {
+      return (
+        <PageContent>
+          <Alert kind={kinds.WARNING}>
+            Diagnostic Scripting is disabled
+          </Alert>
+        </PageContent>
+      );
+    }
+
+    return (
+      <ScriptConsole
+        {...this.props}
+      />
+    );
+  }
+}
+
+ScriptConnector.propTypes = {
+  isStatusPopulated: PropTypes.bool.isRequired,
+  isScriptConsoleEnabled: PropTypes.bool,
+  isExecuting: PropTypes.bool.isRequired,
+  isDebugging: PropTypes.bool.isRequired,
+  isValidating: PropTypes.bool.isRequired,
+  code: PropTypes.string,
+  result: PropTypes.object,
+  error: PropTypes.object,
+  validation: PropTypes.object,
+  fetchStatus: PropTypes.func.isRequired,
+  updateScript: PropTypes.func.isRequired,
+  validateScript: PropTypes.func.isRequired,
+  executeScript: PropTypes.func.isRequired
+};
+
+export default connect(createMapStateToProps, mapDispatchToProps)(ScriptConnector);

frontend/src/Diagnostic/Script/ScriptConsole.css

@@ -0,0 +1,6 @@
+.split {
+  display: flex;
+  justify-content: space-between;
+  overflow: hidden;
+  height: 100%;
+}

frontend/src/Diagnostic/Script/ScriptConsole.js

@@ -0,0 +1,139 @@
+import _ from 'lodash';
+import PropTypes from 'prop-types';
+import React, { Component, lazy, Suspense } from 'react';
+import { icons } from 'Helpers/Props';
+import LoadingIndicator from 'Components/Loading/LoadingIndicator';
+import PageToolbar from 'Components/Page/Toolbar/PageToolbar';
+import PageContent from 'Components/Page/PageContent';
+import PageToolbarSection from 'Components/Page/Toolbar/PageToolbarSection';
+import PageToolbarButton from 'Components/Page/Toolbar/PageToolbarButton';
+import styles from './ScriptConsole.css';
+
+// Lazy load the Monaco Editor since it's a big bundle
+const MonacoEditor = lazy(() => import(/* webpackChunkName: "monaco-editor" */ './MonacoEditor'));
+
+const DefaultOptions = {
+  selectOnLineNumbers: true,
+  scrollBeyondLastLine: false
+};
+const DefaultResultOptions = {
+  ...DefaultOptions,
+  readOnly: true
+};
+
+class ScriptConsole extends Component {
+
+  //
+  // Lifecycle
+
+  editorDidMount = (editor, monaco) => {
+    console.log('editorDidMount', editor);
+    editor.focus();
+    this.monaco = monaco;
+    this.editor = editor;
+
+    this.updateValidation(this.props.validation);
+  }
+
+  updateValidation(validation) {
+    if (!this.monaco) {
+      return;
+    }
+
+    let diagnostics = [];
+
+    if (validation && validation.errorDiagnostics) {
+      diagnostics = validation.errorDiagnostics;
+    }
+
+    const model = this.editor.getModel();
+
+    this.monaco.editor.setModelMarkers(model, 'editor', diagnostics);
+  }
+
+  onChange = (newValue, e) => {
+    this.props.updateScript({ code: newValue });
+
+    this.validateCode();
+  }
+
+  validateCode = _.debounce(() => {
+    const code = this.props.code;
+    this.props.validateScript({ code });
+  }, 250, { leading: false, trailing: true })
+
+  onExecuteScriptPress = () => {
+    const code = this.props.code;
+    this.props.executeScript({ code });
+  }
+
+  onDebugScriptPress = () => {
+    const code = this.props.code;
+    this.props.executeScript({ code, debug: true });
+  }
+
+  //
+  // Render
+  render() {
+    const code = this.props.code;
+    const result = JSON.stringify(this.props.result, null, 2);
+
+    this.updateValidation(this.props.validation);
+
+    return (
+      <PageContent>
+        <PageToolbar>
+          <PageToolbarSection>
+            <PageToolbarButton
+              label="Run"
+              iconName={this.props.isExecuting ? icons.REFRESH : icons.SCRIPT_RUN}
+              isSpinning={this.props.isExecuting}
+              onPress={this.onExecuteScriptPress}
+            />
+            <PageToolbarButton
+              label="Debug"
+              iconName={this.props.isDebugging ? icons.REFRESH : icons.SCRIPT_DEBUG}
+              isSpinning={this.props.isDebugging}
+              onPress={this.onDebugScriptPress}
+            />
+          </PageToolbarSection>
+        </PageToolbar>
+        <Suspense fallback={<LoadingIndicator />}>
+          <div className={styles.split}>
+            <MonacoEditor
+              language="csharp"
+              theme="vs-light"
+              width="50%"
+              value={code}
+              options={DefaultOptions}
+              onChange={this.onChange}
+              editorDidMount={this.editorDidMount}
+            />
+            <MonacoEditor
+              language="json"
+              theme="vs-light"
+              width="50%"
+              value={result}
+              options={DefaultResultOptions}
+            />
+          </div>
+        </Suspense>
+      </PageContent>
+    );
+  }
+}
+
+ScriptConsole.propTypes = {
+  isExecuting: PropTypes.bool.isRequired,
+  isDebugging: PropTypes.bool.isRequired,
+  isValidating: PropTypes.bool.isRequired,
+  code: PropTypes.string,
+  result: PropTypes.object,
+  error: PropTypes.object,
+  validation: PropTypes.object,
+  updateScript: PropTypes.func.isRequired,
+  validateScript: PropTypes.func.isRequired,
+  executeScript: PropTypes.func.isRequired
+};
+
+export default ScriptConsole;

frontend/src/Diagnostic/Status/Statistics/Statistics.css

@@ -0,0 +1,5 @@
+.descriptionList {
+  composes: descriptionList from '~Components/DescriptionList/DescriptionList.css';
+
+  margin-bottom: 10px;
+}

frontend/src/Diagnostic/Status/Statistics/Statistics.js

@@ -0,0 +1,93 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import FieldSet from 'Components/FieldSet';
+import DescriptionList from 'Components/DescriptionList/DescriptionList';
+import DescriptionListItem from 'Components/DescriptionList/DescriptionListItem';
+import styles from './Statistics.css';
+import formatBytes from 'Utilities/Number/formatBytes';
+import formatTimeSpan from 'Utilities/Date/formatTimeSpan';
+import moment from 'moment';
+
+function formatValue(val, formatter) {
+  if (val === undefined) {
+    return 'n/a';
+  }
+
+  if (formatter) {
+    return formatter(val);
+  }
+
+  return val;
+}
+
+class Statistics extends Component {
+
+  //
+  // Render
+
+  render() {
+    const {
+      process,
+      databaseMain,
+      databaseLog,
+      commandsExecuted
+    } = this.props;
+
+    return (
+      <FieldSet legend="Statistics">
+        <DescriptionList className={styles.descriptionList}>
+          <DescriptionListItem
+            title="Up Time"
+            data={formatValue(process.startTime, (startTime) => formatTimeSpan(moment().diff(startTime)))}
+          />
+
+          <DescriptionListItem
+            title="Processor Time"
+            data={formatValue(process.totalProcessorTime, formatTimeSpan)}
+          />
+
+          <DescriptionListItem
+            title="Memory Working Set"
+            data={formatValue(process.workingSet, formatBytes)}
+          />
+
+          <DescriptionListItem
+            title="Memory Virtual Size"
+            data={formatValue(process.virtualMemorySize, formatBytes)}
+          />
+
+          <DescriptionListItem
+            title="Main Database Size"
+            data={formatValue(databaseMain.size, formatBytes)}
+          />
+
+          <DescriptionListItem
+            title="Logs Database Size"
+            data={formatValue(databaseLog.size, formatBytes)}
+          />
+
+          <DescriptionListItem
+            title="Commands Executed"
+            data={formatValue(commandsExecuted, formatBytes)}
+          />
+        </DescriptionList>
+      </FieldSet>
+    );
+  }
+
+}
+
+Statistics.propTypes = {
+  process: PropTypes.object,
+  databaseMain: PropTypes.object,
+  databaseLog: PropTypes.object,
+  commandsExecuted: PropTypes.number
+};
+
+Statistics.defaultProps = {
+  process: {},
+  databaseMain: {},
+  databaseLog: {}
+};
+
+export default Statistics;

frontend/src/Diagnostic/Status/Status.js

@@ -0,0 +1,46 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import { icons } from 'Helpers/Props';
+import PageContent from 'Components/Page/PageContent';
+import PageContentBody from 'Components/Page/PageContentBody';
+import PageToolbar from 'Components/Page/Toolbar/PageToolbar';
+import PageToolbarSection from 'Components/Page/Toolbar/PageToolbarSection';
+import PageToolbarButton from 'Components/Page/Toolbar/PageToolbarButton';
+import Statistics from './Statistics/Statistics';
+
+class Status extends Component {
+
+  //
+  // Render
+
+  render() {
+    return (
+      <PageContent title="Diagnostic Status">
+        <PageToolbar>
+          <PageToolbarSection>
+            <PageToolbarButton
+              label="Refresh"
+              iconName={icons.REFRESH}
+              isSpinning={this.props.isStatusFetching}
+              onPress={this.props.onRefreshPress}
+            />
+          </PageToolbarSection>
+        </PageToolbar>
+        <PageContentBody>
+          <Statistics
+            {...this.props.status}
+          />
+        </PageContentBody>
+      </PageContent>
+    );
+  }
+
+}
+
+Status.propTypes = {
+  status: PropTypes.object.isRequired,
+  isStatusFetching: PropTypes.bool.isRequired,
+  onRefreshPress: PropTypes.func.isRequired
+};
+
+export default Status;

frontend/src/Diagnostic/Status/StatusConnector.js

@@ -0,0 +1,59 @@
+// @ts-check
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import { connect } from 'react-redux';
+import { createSelector } from 'reselect';
+import { fetchStatus } from 'Store/Actions/diagnosticActions';
+import Status from './Status';
+
+function createMapStateToProps() {
+  return createSelector(
+    (state) => state.diagnostic.status,
+    (status) => {
+      return {
+        isStatusFetching: status.isFetching,
+        status: status.item
+      };
+    }
+  );
+}
+
+const mapDispatchToProps = {
+  fetchStatus
+};
+
+class DiagnosticConnector extends Component {
+
+  //
+  // Lifecycle
+
+  componentDidMount() {
+    this.props.fetchStatus();
+  }
+
+  //
+  // Listeners
+
+  onRefreshPress = () => {
+    this.props.fetchStatus();
+  }
+
+  //
+  // Render
+
+  render() {
+    return (
+      <Status
+        onRefreshPress={this.onRefreshPress}
+        {...this.props}
+      />
+    );
+  }
+}
+
+DiagnosticConnector.propTypes = {
+  status: PropTypes.object.isRequired,
+  fetchStatus: PropTypes.func.isRequired
+};
+
+export default connect(createMapStateToProps, mapDispatchToProps)(DiagnosticConnector);

frontend/src/Helpers/Props/icons.js

@@ -81,6 +81,7 @@ import {
   faSignOutAlt as fasSignOutAlt,
   faSitemap as fasSitemap,
   faSpinner as fasSpinner,
+  faStepForward as fasStepForward,
   faSort as fasSort,
   faSortDown as fasSortDown,
   faSortUp as fasSortUp,
@@ -126,6 +127,7 @@ export const CLONE = farClone;
 export const COLLAPSE = fasChevronCircleUp;
 export const COMPUTER = fasDesktop;
 export const DANGER = fasExclamationCircle;
+export const DEBUG = fasBug;
 export const DELETE = fasTrashAlt;
 export const DOWNLOAD = fasDownload;
 export const DOWNLOADED = fasDownload;
@@ -180,6 +182,8 @@ export const REORDER = fasBars;
 export const RSS = fasRss;
 export const SAVE = fasSave;
 export const SCHEDULED = farClock;
+export const SCRIPT_DEBUG = fasStepForward;
+export const SCRIPT_RUN = fasPlay;
 export const SCORE = fasUserPlus;
 export const SEARCH = fasSearch;
 export const SERIES_CONTINUING = fasPlay;

frontend/src/Store/Actions/diagnosticActions.js

@@ -0,0 +1,185 @@
+import { createThunk, handleThunks } from 'Store/thunks';
+import createFetchHandler from './Creators/createFetchHandler';
+import createHandleActions from './Creators/createHandleActions';
+import createAjaxRequest from 'Utilities/createAjaxRequest';
+import { set } from './baseActions';
+
+//
+// Variables
+
+export const section = 'diagnostic';
+const scriptSection = 'diagnostic.script';
+
+//
+// State
+
+const exampleScript = `// Obtain the instance of ISeriesService
+var seriesService = Resolve<ISeriesService>();
+
+// Get all series
+var series = seriesService.GetAllSeries();
+
+// Find the top 5 highest rated ones
+var top5 = series.Where(s => s.Ratings.Votes > 6)
+                 .OrderByDescending(s => s.Ratings.Value)
+                 .Take(5)
+                 .Select(s => s.Title);
+
+return new {
+  Top5 = top5,
+  Count = series.Count()
+};`;
+
+export const defaultState = {
+  status: {
+    isFetching: false,
+    isPopulated: false,
+    error: null,
+    item: {}
+  },
+
+  script: {
+    isExecuting: false,
+    isDebugging: false,
+    isValidating: false,
+    workspaceId: null,
+    code: exampleScript,
+    validation: null,
+    result: null,
+    error: null
+  }
+};
+
+//
+// Actions Types
+
+export const FETCH_STATUS = 'diagnostic/status/fetchStatus';
+export const UPDATE_SCRIPT = 'diagnostic/script/update';
+export const VALIDATE_SCRIPT = 'diagnostic/script/validate';
+export const EXECUTE_SCRIPT = 'diagnostic/script/execute';
+
+//
+// Action Creators
+
+export const fetchStatus = createThunk(FETCH_STATUS);
+export const updateScript = createThunk(UPDATE_SCRIPT);
+export const validateScript = createThunk(VALIDATE_SCRIPT);
+export const executeScript = createThunk(EXECUTE_SCRIPT);
+
+//
+// Action Handlers
+
+export const actionHandlers = handleThunks({
+  [FETCH_STATUS]: createFetchHandler('diagnostic.status', '/diagnostic/status'),
+
+  [UPDATE_SCRIPT]: function(getState, payload, dispatch) {
+    const {
+      code
+    } = payload;
+
+    dispatch(set({
+      section: scriptSection,
+      code
+    }));
+  },
+
+  [VALIDATE_SCRIPT]: function(getState, payload, dispatch) {
+    const {
+      code
+    } = payload;
+
+    dispatch(set({
+      section: scriptSection,
+      code,
+      isValidating: true
+    }));
+
+    let ajaxOptions = null;
+
+    ajaxOptions = {
+      url: '/diagnostic/script/validate',
+      method: 'POST',
+      contentType: 'application/json',
+      dataType: 'json',
+      data: JSON.stringify({
+        code
+      })
+    };
+
+    const promise = createAjaxRequest(ajaxOptions).request;
+
+    promise.done((data) => {
+      dispatch(set({
+        section: scriptSection,
+        isValidating: false,
+        validation: data
+      }));
+    });
+
+    promise.fail((xhr) => {
+      dispatch(set({
+        section: scriptSection,
+        isValidating: false,
+        validation: null,
+        error: xhr
+      }));
+    });
+  },
+
+  [EXECUTE_SCRIPT]: function(getState, payload, dispatch) {
+    const {
+      code,
+      debug
+    } = payload;
+
+    dispatch(set({
+      section: scriptSection,
+      code,
+      isExecuting: !debug,
+      isDebugging: debug
+    }));
+
+    let ajaxOptions = null;
+
+    ajaxOptions = {
+      url: '/diagnostic/script/execute',
+      method: 'POST',
+      contentType: 'application/json',
+      dataType: 'json',
+      data: JSON.stringify({
+        code,
+        debug
+      })
+    };
+
+    const promise = createAjaxRequest(ajaxOptions).request;
+
+    promise.done((data) => {
+      dispatch(set({
+        section: scriptSection,
+        isExecuting: false,
+        isDebugging: false,
+        result: (debug || data.error) ? data : data.returnValue,
+        validation: {
+          errorDiagnostics: data.errorDiagnostics
+        }
+      }));
+    });
+
+    promise.fail((xhr) => {
+      dispatch(set({
+        section: scriptSection,
+        isExecuting: false,
+        isDebugging: false,
+        error: xhr
+      }));
+    });
+  }
+});
+
+//
+// Reducers
+
+export const reducers = createHandleActions({
+
+}, defaultState, section);

frontend/src/Store/Actions/index.js

@@ -5,6 +5,7 @@ import * as calendar from './calendarActions';
 import * as captcha from './captchaActions';
 import * as customFilters from './customFilterActions';
 import * as commands from './commandActions';
+import * as diagnostic from './diagnosticActions';
 import * as episodes from './episodeActions';
 import * as episodeFiles from './episodeFileActions';
 import * as episodeHistory from './episodeHistoryActions';
@@ -36,6 +37,7 @@ export default [
   captcha,
   commands,
   customFilters,
+  diagnostic,
   episodes,
   episodeFiles,
   episodeHistory,

package.json

@@ -77,6 +77,7 @@
     "mini-css-extract-plugin": "0.8.0",
     "mobile-detect": "1.4.3",
     "moment": "2.24.0",
+    "monaco-editor": "0.20.0",
     "mousetrap": "1.6.3",
     "normalize.css": "8.0.1",
     "postcss-color-function": "4.1.0",
@@ -100,6 +101,7 @@
     "react-google-recaptcha": "1.1.0",
     "react-lazyload": "2.6.2",
     "react-measure": "1.4.7",
+    "react-monaco-editor": "0.36.0",
     "react-popper": "1.3.3",
     "react-redux": "7.1.0",
     "react-router": "5.0.1",

src/NzbDrone.Core.Test/DiagnosticsTests/DiagnosticScriptRunnerFixture.cs

@@ -0,0 +1,89 @@
+using System.Linq;
+using FizzWare.NBuilder;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common.Composition;
+using NzbDrone.Common.Disk;
+using NzbDrone.Core.Diagnostics;
+using NzbDrone.Core.Test.Framework;
+using NzbDrone.Core.Tv;
+using NzbDrone.Test.Common;
+
+namespace NzbDrone.Core.Test.DiagnosticsTests
+{
+    public class DiagnosticScriptRunnerFixture : CoreTest<DiagnosticScriptRunner>
+    {
+        [TestCase("1 ++ 2", "(1,6): error CS1002: ; expected")]
+        [TestCase("a = 2", "(1,1): error CS0103: The name 'a' does not exist in the current context")]
+        [TestCase("Logger.NoMethod()", "(1,8): error CS1061: 'Logger' does not contain a definition for 'NoMethod' and no accessible extension method 'NoMethod' accepting a first argument of type 'Logger' could be found (are you missing a using directive or an assembly reference?)")]
+        public void Validate_should_list_compiler_errors(string source, string message)
+        {
+            var result = Subject.Validate(new ScriptRequest { Code = source, Debug = true });
+
+            result.HasErrors.Should().BeTrue();
+            result.Messages.First().FullMessage.Should().Be("ScriptConsole.cs" + message);
+        }
+
+        [Test]
+        public void Execute_should_show_context()
+        {
+            var result = Subject.Execute(new ScriptRequest { Code = "var a = 12;" });
+
+            result.ReturnValue.Should().BeNull();
+            result.Variables.Should().HaveCount(1);
+            result.Variables["a"].Should().Be(12);
+        }
+
+        [Test]
+        public void Execute_should_allow_continuations()
+        {
+            var result = Subject.Execute(new ScriptRequest { Code = "var a = 12;", StoreState = true });
+
+            var result2 = Subject.Execute(new ScriptRequest { Code = "var b = a + 2;", StateId = result.StateId });
+
+            result2.Variables.Should().HaveCount(2);
+            result2.Variables["b"].Should().Be(14);
+        }
+
+        [Test]
+        public void Execute_should_resolve_interfaces_Common()
+        {
+            Mocker.SetConstant<IContainer>(new AutoMoqerContainer(Mocker));
+
+            Mocker.GetMock<IDiskProvider>()
+                .Setup(v => v.FolderExists("C:\test"))
+                .Returns(true);
+
+            var result = Subject.Execute(new ScriptRequest { Code = @"
+            var diskProvider = Resolve<IDiskProvider>();
+
+            return diskProvider.FolderExists(""C:\test"") ? ""yes"" : ""no"";
+            " });
+
+            result.ReturnValue.Should().Be("yes");
+        }
+
+        [Test]
+        public void Execute_should_resolve_interfaces_Core()
+        {
+            Mocker.SetConstant<IContainer>(new AutoMoqerContainer(Mocker));
+
+            Mocker.GetMock<ISeriesService>()
+                .Setup(v => v.GetAllSeries())
+                .Returns(Builder<Series>.CreateListOfSize(5).BuildList());
+
+            var result = Subject.Execute(new ScriptRequest { Code = @"
+            var seriesService = Resolve<ISeriesService>();
+
+            foreach (var series in seriesService.GetAllSeries())
+            {
+                await Task.Delay(1000);
+                Logger.Debug($""Processing series {series.Title}"");
+            }
+            return ""done"";
+            " });
+
+            result.ReturnValue.Should().Be("done");
+        }
+    }
+}

src/NzbDrone.Core/Datastore/Database.cs

@@ -9,6 +9,7 @@ namespace NzbDrone.Core.Datastore
     {
         IDataMapper GetDataMapper();
         Version Version { get; }
+        long Size { get; }
         void Vacuum();
     }
 
@@ -39,6 +40,16 @@ namespace NzbDrone.Core.Datastore
             }
         }
 
+        public long Size
+        {
+            get
+            {
+                var page_count = _datamapperFactory().ExecuteScalar("PRAGMA page_count;");
+                var page_size = _datamapperFactory().ExecuteScalar("PRAGMA page_size;");
+                return Convert.ToInt64(page_count) * Convert.ToInt64(page_size);
+            }
+        }
+
         public void Vacuum()
         {
             try

src/NzbDrone.Core/Datastore/LogDatabase.cs

@@ -23,6 +23,8 @@ namespace NzbDrone.Core.Datastore
         }
 
         public Version Version => _database.Version;
+        public long Size => _database.Size;
+
 
         public void Vacuum()
         {

src/NzbDrone.Core/Datastore/MainDatabase.cs

@@ -23,6 +23,7 @@ namespace NzbDrone.Core.Datastore
         }
 
         public Version Version => _database.Version;
+        public long Size => _database.Size;
 
         public void Vacuum()
         {

src/NzbDrone.Core/Diagnostics/DiagnosticFeatureSwitches.cs

@@ -0,0 +1,38 @@
+using System.IO;
+using NzbDrone.Common.Disk;
+using NzbDrone.Common.EnvironmentInfo;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public interface IDiagnosticFeatureSwitches
+    {
+        bool ScriptConsoleEnabled { get; }
+    }
+
+    public class DiagnosticFeatureSwitches : IDiagnosticFeatureSwitches
+    {
+        private IDiskProvider _diskProvider;
+        private IAppFolderInfo _appFolderInfo;
+
+        public DiagnosticFeatureSwitches(IDiskProvider diskProvider, IAppFolderInfo appFolderInfo)
+        {
+            _diskProvider = diskProvider;
+            _appFolderInfo = appFolderInfo;
+        }
+
+        public bool ScriptConsoleEnabled
+        {
+            get
+            {
+                // Only allow this if the 'debugscripts' config folder exists.
+                // Scripting is a significant security risk with only an api key for protection.
+                if (!_diskProvider.FolderExists(Path.Combine(_appFolderInfo.AppDataFolder, "debugscripts")))
+                {
+                    return false;
+                }
+
+                return true;
+            }
+        }
+    }
+}

src/NzbDrone.Core/Diagnostics/DiagnosticScriptRunner.cs

@@ -0,0 +1,397 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Scripting;
+using Microsoft.CodeAnalysis.Scripting;
+using NLog;
+using NzbDrone.Common.Cache;
+using NzbDrone.Common.Composition;
+using NzbDrone.Common.EnvironmentInfo;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public interface IDiagnosticScriptRunner
+    {
+        ScriptValidationResult Validate(ScriptRequest request);
+        ScriptExecutionResult Execute(ScriptRequest request);
+    }
+    internal class CompilationContext
+    {
+        public HashSet<string> GlobalUsings { get; set; }
+        public ScriptOptions Options { get; set; }
+        public string Code { get; set; }
+        public Script Script { get; set; }
+        public Compilation LastCompilation { get; set; }
+    }
+
+    public class DiagnosticScriptRunner : IDiagnosticScriptRunner
+    {
+        private static readonly Regex _regexResolve = new Regex(@"=\s+Resolve<(I\w+)>", RegexOptions.Compiled);
+        private static readonly Assembly[] _assemblies = new[] {
+            typeof(AppFolderInfo).Assembly,
+            typeof(DiagnosticScriptRunner).Assembly
+        };
+
+        private readonly IContainer _container;
+        private readonly Logger _logger;
+
+        private readonly ICached<object> _scriptStateCache;
+
+        private WeakReference<CompilationContext> _lastCompilation;
+
+        public DiagnosticScriptRunner(IContainer container, ICacheManager cacheManager, Logger logger)
+        {
+            _container = container;
+            _logger = logger;
+
+            // Note: using object instead of ScriptState to avoid the Scripting assembly to be loaded on startup.
+            _scriptStateCache = cacheManager.GetCache<object>(GetType());
+
+            _lastCompilation = new WeakReference<CompilationContext>(null);
+
+            CheckScriptingAssemblyDelayLoad();
+        }
+
+        private void CheckScriptingAssemblyDelayLoad()
+        {
+            var scriptingLoaded = AppDomain.CurrentDomain.GetAssemblies().Any(v => v.FullName.Contains("Microsoft.CodeAnalysis"));
+            if (scriptingLoaded)
+            {
+                // If we reach this code, then the class has been changed and as a result the Microsoft.CodeAnalysis.CSharp.Scripting assembly
+                // was loaded on startup. This should be avoided since it takes more memory and is not used in normal situations.
+                if (!RuntimeInfo.IsProduction)
+                {
+                    _logger.Error("Scripting assembly loaded prematurely.");
+                }
+                if (Debugger.IsAttached)
+                {
+                    Debugger.Break();
+                }
+            }
+        }
+
+        public ScriptValidationResult Validate(ScriptRequest request)
+        {
+            lock (this)
+            {
+                var globalUsings = GetGlobalUsings(request.Code);
+
+                _lastCompilation.TryGetTarget(out var lastCompilation);
+
+                // Swapping SyntaxTree is significantly faster and uses less memory
+                if (lastCompilation != null && lastCompilation.Code == request.Code)
+                {
+                    // Unchanged
+                }
+                else if (lastCompilation != null && lastCompilation.GlobalUsings == globalUsings)
+                {
+                    var newSyntaxTree = CSharpSyntaxTree.ParseText(request.Code, CSharpParseOptions.Default.WithKind(SourceCodeKind.Script));
+
+                    lastCompilation.Script = null;
+                    lastCompilation.Code = request.Code;
+                    lastCompilation.LastCompilation = lastCompilation.LastCompilation.ReplaceSyntaxTree(lastCompilation.LastCompilation.SyntaxTrees.First(), newSyntaxTree);
+                }
+                else
+                {
+                    var options = GetOptions(globalUsings, request.Debug);
+
+                    var script = CSharpScript.Create(request.Code, options, globalsType: typeof(ScriptContext));
+
+                    var compilation = script.GetCompilation();
+
+                    lastCompilation = new CompilationContext
+                    {
+                        GlobalUsings = globalUsings,
+                        Options = options,
+                        Code = request.Code,
+                        Script = script,
+                        LastCompilation = compilation
+                    };
+
+                    _lastCompilation.SetTarget(lastCompilation);
+                }
+
+                var diagnostics = lastCompilation.LastCompilation.GetDiagnostics();
+
+                return new ScriptValidationResult
+                {
+                    Messages = diagnostics.Select(v => new ScriptDiagnostic(v)).ToArray()
+                };
+            }
+        }
+
+        public ScriptExecutionResult Execute(ScriptRequest request)
+        {
+            if (request.StateId != null)
+            {
+                return ExecuteAsync(request, request.StateId).GetAwaiter().GetResult();
+            }
+            else
+            {
+                return ExecuteAsync(request).GetAwaiter().GetResult();
+            }
+        }
+
+        public Task<ScriptExecutionResult> ExecuteAsync(ScriptRequest request)
+        {
+            Script script;
+
+            lock (this)
+            {
+                var globalUsings = GetGlobalUsings(request.Code);
+
+                _lastCompilation.TryGetTarget(out var lastCompilation);
+
+                if (lastCompilation != null && lastCompilation.Code == request.Code && lastCompilation.Script != null &&
+                    lastCompilation.Options.EmitDebugInformation == request.Debug)
+                {
+                    script = lastCompilation.Script;
+                }
+                else
+                {
+                    try
+                    {
+                        var options = GetOptions(globalUsings, request.Debug);
+
+                        // Note: Using classic Task pipeline since async-await early loads the Scripts assembly
+                        script = CSharpScript.Create(request.Code, options, globalsType: typeof(ScriptContext));
+
+                        var compilation = script.GetCompilation();
+
+                        lastCompilation = new CompilationContext
+                        {
+                            GlobalUsings = globalUsings,
+                            Options = options,
+                            Code = request.Code,
+                            Script = script,
+                            LastCompilation = compilation
+                        };
+
+                        _lastCompilation.SetTarget(lastCompilation);
+                    }
+                    catch (CompilationErrorException ex)
+                    {
+                        return Task.FromResult(GetResult(ex));
+                    }
+                }
+            }
+
+            try
+            {
+                return script.RunAsync(new ScriptContext(_container, _logger), ex => true).ContinueWith(t =>
+                {
+                    var state = t.Result;
+
+                    if (state.Exception != null)
+                    {
+                        return GetResult(state.Exception, request.Code);
+                    }
+                    else
+                    {
+                        return GetResult(state, request.StoreState);
+                    }
+                });
+            }
+            catch (CompilationErrorException ex)
+            {
+                return Task.FromResult(GetResult(ex));
+            }
+        }
+
+        public Task<ScriptExecutionResult> ExecuteAsync(ScriptRequest request, string stateId)
+        {
+            var options = GetOptions(GetGlobalUsings(request.Code), request.Debug);
+
+            var script = GetState(stateId);
+
+            try
+            {
+                // Note: Using classic Task pipeline since async-await early loads the Scripts assembly
+                return script.ContinueWithAsync(request.Code, options, ex => true).ContinueWith(t =>
+                {
+                    var state = t.Result;
+
+                    if (state.Exception != null)
+                    {
+                        return GetResult(state.Exception, request.Code);
+                    }
+                    else
+                    {
+                        return GetResult(state, request.StoreState);
+                    }
+                });
+            }
+            catch (CompilationErrorException ex)
+            {
+                return Task.FromResult(GetResult(ex));
+            }
+        }
+
+        private HashSet<string> GetGlobalUsings(string source)
+        {
+            var result = new HashSet<string>();
+
+            // Make the syntax easier by parsing Resolve<I..> and auto add using
+            var matches = _regexResolve.Matches(source);
+            foreach (Match match in matches)
+            {
+                foreach (var ns in ResolveNamespaces(match.Groups[1].Value))
+                {
+                    result.Add(ns);
+                }
+            }
+
+            return result;
+        }
+
+        private ScriptOptions GetOptions(HashSet<string> globalUsings, bool debug = false)
+        {
+            var options = ScriptOptions.Default
+                .AddReferences(_assemblies)
+                .AddImports(typeof(Task).Namespace)
+                .AddImports(typeof(Enumerable).Namespace);
+
+            if (debug)
+            {
+                options = options.WithEmitDebugInformation(true)
+                                 .WithFilePath("ScriptConsole.cs")
+                                 .WithFileEncoding(Encoding.UTF8);
+            }
+
+            // Make the syntax easier by parsing Resolve<I..> and auto add using
+            foreach (var ns in globalUsings)
+            {
+                options = options.AddImports(ns);
+            }
+
+            return options;
+        }
+
+        private List<string> ResolveNamespaces(string type)
+        {
+            var types = _assemblies
+                .SelectMany(v => v.GetExportedTypes())
+                .Where(v => v.Name == type);
+
+            var namespaces = types.Select(v => v.Namespace)
+                .Distinct()
+                .ToList();
+
+            return namespaces;
+        }
+
+        private ScriptExecutionResult GetResult(ScriptState state, bool storeState)
+        {
+            var variables = state.Variables.Where(v => !v.Type.IsInterface || !v.Type.Namespace.StartsWith("NzbDrone")).ToDictionary(v => v.Name, v => v.Value);
+
+            var result = new ScriptExecutionResult
+            {
+                StateId = storeState ? StoreState(state) : null,
+                ReturnValue = state.ReturnValue,
+                Variables = variables.Any() ? variables : null
+            };
+
+            return result;
+        }
+
+        private ScriptExecutionResult GetResult(CompilationErrorException ex)
+        {
+            return new ScriptExecutionResult
+            {
+                Exception = ex,
+                Validation = new ScriptValidationResult { Messages = ex.Diagnostics.Select(v => new ScriptDiagnostic(v)).ToArray() }
+            };
+        }
+        
+        private ScriptExecutionResult GetResult(Exception ex, string code)
+        {
+            var result = new ScriptExecutionResult
+            {
+                Exception = ex
+            };
+
+            StackFrame firstScriptFrame = null;
+            var stackTrace = new StackTrace(ex, true);
+            
+            for (int i = 0; i < stackTrace.FrameCount; i++)
+            {
+                var frame = stackTrace.GetFrame(i);
+                if (frame.GetFileName() == "ScriptConsole.cs" && result.Validation == null)
+                {
+                    firstScriptFrame = frame;
+                    break;
+                }
+            }
+
+            // Get the full message text till the scripting runtime
+            var fullMessage = ex.ToString();
+            var fullMessageLines = fullMessage.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
+            var idx = Array.FindIndex(fullMessageLines, 1, v => v.Contains("RunSubmissionsAsync")) - 2;
+            if (idx > 2 && fullMessageLines[idx - 1].StartsWith("---"))
+            {
+                idx--;
+            }
+
+            if (idx > 1)
+            {
+                fullMessage = string.Join("\n", fullMessageLines.Take(idx));
+            }
+
+            var lines = code.Split('\n');
+            ScriptDiagnostic diagnostic;
+            if (firstScriptFrame != null)
+            {
+                var startLineNumber = firstScriptFrame.GetFileLineNumber();
+                var startColumn = firstScriptFrame.GetFileColumnNumber();
+                var endLineNumber = startLineNumber;
+                var endColumn = startColumn == 1 ? lines[startLineNumber - 1].Length : startColumn;
+                diagnostic = new ScriptDiagnostic(ex, startLineNumber, startColumn, endLineNumber, endColumn, fullMessage);
+            }
+            else
+            {
+                diagnostic = new ScriptDiagnostic(ex, 1, 1, lines.Length, lines.Last().Length, fullMessage);
+            }
+
+            result.Validation = new ScriptValidationResult
+            {
+                Messages = new[]
+                {
+                    diagnostic
+                }
+            };
+
+            return result;
+        }
+
+        private ScriptState GetState(string stateID)
+        {
+            var state = _scriptStateCache.Find(stateID);
+
+            if (state == null)
+                throw new KeyNotFoundException($"ScriptState {stateID} no longer exists");
+
+            return state as ScriptState;
+        }
+
+        private void RemoveState(string stateID)
+        {
+            _scriptStateCache.Remove(stateID);
+        }
+
+        private string StoreState(ScriptState state)
+        {
+            var key = Guid.NewGuid().ToString();
+
+            _scriptStateCache.Set(key, state, TimeSpan.FromHours(1));
+
+            return key;
+        }
+    }
+}

src/NzbDrone.Core/Diagnostics/ScriptContext.cs

@@ -0,0 +1,25 @@
+using NLog;
+using NzbDrone.Common.Composition;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public class ScriptContext
+    {
+        private readonly IContainer _container;
+        private readonly Logger _logger;
+
+        public ScriptContext(IContainer container, Logger logger)
+        {
+            _container = container;
+            _logger = logger;
+        }
+
+        public Logger Logger => _logger;
+
+        public T Resolve<T>()
+             where T : class
+        {
+            return _container.Resolve<T>();
+        }
+    }
+}

src/NzbDrone.Core/Diagnostics/ScriptDiagnostic.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Diagnostics;
+using Microsoft.CodeAnalysis;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public enum ScriptDiagnosticSeverity
+    {
+        Info = 1,
+        Warning = 2,
+        Error = 3
+    }
+
+    public class ScriptDiagnostic
+    {
+        public int StartLineNumber { get; set; }
+        public int StartColumn { get; set; }
+        public int EndLineNumber { get; set; }
+        public int EndColumn { get; set; }
+        public string Message { get; set; }
+        public ScriptDiagnosticSeverity Severity { get; set; }
+        public string FullMessage { get; set; }
+
+        public ScriptDiagnostic()
+        {
+        }
+
+        public ScriptDiagnostic(Exception ex, int startLineNumber, int startColumn, int endLineNumber, int endColumn, string fullMessage)
+        {
+            StartLineNumber = startLineNumber;
+            StartColumn = startColumn;
+            EndLineNumber = endLineNumber;
+            EndColumn = endColumn;
+            Message = ex.Message;
+            Severity = ScriptDiagnosticSeverity.Error;
+            FullMessage = fullMessage;
+        }
+
+        public ScriptDiagnostic(Diagnostic diagnostic)
+        {
+            var lineSpan = diagnostic.Location.GetLineSpan();
+
+            StartLineNumber = lineSpan.StartLinePosition.Line + 1;
+            StartColumn = lineSpan.StartLinePosition.Character + 1;
+            EndLineNumber = lineSpan.EndLinePosition.Line + 1;
+            EndColumn = lineSpan.EndLinePosition.Character + 1;
+            Message = diagnostic.GetMessage();
+            Severity = (ScriptDiagnosticSeverity)diagnostic.Severity;
+            FullMessage = diagnostic.ToString();
+        }
+    }
+}

src/NzbDrone.Core/Diagnostics/ScriptExecutionResult.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public class ScriptExecutionResult
+    {
+        public string StateId { get; set; }
+
+        public Exception Exception { get; set; }
+        public object ReturnValue { get; set; }
+        public Dictionary<string, object> Variables { get; set; }
+        public ScriptValidationResult Validation { get; set; }
+    }
+}

src/NzbDrone.Core/Diagnostics/ScriptRequest.cs

@@ -0,0 +1,11 @@
+namespace NzbDrone.Core.Diagnostics
+{
+    public class ScriptRequest
+    {
+        public string Name { get; set; }
+        public string Code { get; set; }
+        public string StateId { get; set; }
+        public bool Debug { get; set; }
+        public bool StoreState { get; set; }
+    }
+}

src/NzbDrone.Core/Diagnostics/ScriptValidationResult.cs

@@ -0,0 +1,14 @@
+using System.Linq;
+using Microsoft.CodeAnalysis;
+
+namespace NzbDrone.Core.Diagnostics
+{
+    public class ScriptValidationResult
+    {
+        public ScriptDiagnostic[] Messages { get; set; }
+
+        public bool HasWarnings => Messages.Any(v => v.Severity == ScriptDiagnosticSeverity.Warning);
+        public bool HasErrors => Messages.Any(v => v.Severity == ScriptDiagnosticSeverity.Error);
+
+    }
+}

src/NzbDrone.Core/Sonarr.Core.csproj

@@ -8,6 +8,7 @@
     <PackageReference Include="FluentValidation" Version="8.4.0" />
     <PackageReference Include="SixLabors.ImageSharp.Drawing" Version="1.0.0-beta0007" />
     <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="3.6.0" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
     <PackageReference Include="NLog" Version="4.6.6" />
     <PackageReference Include="OAuth" Version="1.0.3" />

src/NzbDrone.Integration.Test/DiagnosticsTests/DiagnosticsScriptModuleFixture.cs

@@ -0,0 +1,199 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Text;
+using System.Threading.Tasks;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Core.Diagnostics;
+using NzbDrone.Integration.Test.Client;
+using RestSharp;
+using Sonarr.Api.V3.Diagnostics;
+
+namespace NzbDrone.Integration.Test.DiagnosticsTests
+{
+    public class DiagnosticScriptResource
+    {
+        public string Code { get; set; }
+        public bool? Debug { get; set; }
+
+        public object ReturnValue { get; set; }
+        public Dictionary<string, object> DebugVariables { get; set; }
+
+        public string Error { get; set; }
+        public List<ScriptDiagnostic> ErrorDiagnostics { get; set; }
+    }
+
+    public class DiagnosticsScriptClient : ClientBase
+    {
+        public DiagnosticsScriptClient(IRestClient restClient, string apiKey)
+            : base(restClient, apiKey, "v3/diagnostic/script")
+        {
+        }
+
+        public DiagnosticScriptResource Execute(DiagnosticScriptResource body, HttpStatusCode statusCode = HttpStatusCode.OK)
+        {
+            var request = BuildRequest("execute");
+            request.Method = Method.POST;
+            request.AddJsonBody(body);
+            return Execute<DiagnosticScriptResource>(request, statusCode);
+        }
+    }
+
+    public class DiagnosticsScriptModuleFixture : IntegrationTest
+    {
+        DiagnosticsScriptClient DiagScript { get; set; }
+
+        [SetUp]
+        public void SetUp()
+        {
+            DiagScript = new DiagnosticsScriptClient(RestClient, ApiKey);
+        }
+
+        private void GivenEnabledFeature(bool enabled = true)
+        {
+            var debugscripts = Path.Combine(_runner.AppData, "debugscripts");
+
+            if (enabled && !Directory.Exists(debugscripts))
+            {
+                Directory.CreateDirectory(debugscripts);
+            }
+            else if (!enabled && Directory.Exists(debugscripts))
+            {
+                Directory.Delete(debugscripts);
+            }
+        }
+
+        [Test]
+        public void should_not_allow_access_without_debugscripts_dir()
+        {
+            GivenEnabledFeature(false);
+
+            DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "return \"abc\";"
+            }, HttpStatusCode.NotFound);
+        }
+
+        [Test]
+        public void should_not_allow_access_with_debugscripts_dir()
+        {
+            GivenEnabledFeature(true);
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "return \"abc\";"
+            });
+
+            result.ReturnValue.Should().Be("abc");
+        }
+
+        [Test]
+        public void should_include_variables_for_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var a = \"abc\";",
+                Debug = true
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().Contain("a", "abc");
+        }
+
+        [Test]
+        public void should_not_include_variables_without_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var a = \"abc\";"
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().BeNull();
+        }
+
+        [Test]
+        public void should_report_compile_errors_with_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var a = \"abc\" + b;",
+                Debug = true
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().BeNull();
+            result.Error.Should().Be("ScriptConsole.cs(1,17): error CS0103: The name 'b' does not exist in the current context");
+            result.ErrorDiagnostics.Should().NotBeNull();
+            result.ErrorDiagnostics.First().Message.Should().Be("The name 'b' does not exist in the current context");
+        }
+
+        [Test]
+        public void should_report_compile_errors_without_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var a = \"abc\" + b;"
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().BeNull();
+            result.Error.Should().Be("(1,17): error CS0103: The name 'b' does not exist in the current context");
+            result.ErrorDiagnostics.Should().NotBeNull();
+            result.ErrorDiagnostics.First().Message.Should().Be("The name 'b' does not exist in the current context");
+        }
+
+        [Test]
+        public void should_report_execution_errors_with_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var seriesService = Resolve<ISeriesService>();\nseriesService.AddSeries((Series)null);",
+                Debug = true
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().BeNull();
+            result.Error.Should().StartWith("Object reference not set to an instance of an object");
+            result.ErrorDiagnostics.Should().NotBeNull();
+            result.ErrorDiagnostics.First().StartLineNumber.Should().Be(2);
+            result.ErrorDiagnostics.First().StartColumn.Should().Be(1);
+            result.ErrorDiagnostics.First().Message.Should().StartWith("Object reference not set to an instance of an object");
+            result.ErrorDiagnostics.First().FullMessage.Should().StartWith("System.NullReferenceException: Object reference not set to an instance of an object");
+        }
+
+        [Test]
+        public void should_report_execution_errors_without_debug()
+        {
+            GivenEnabledFeature();
+
+            var result = DiagScript.Execute(new DiagnosticScriptResource
+            {
+                Code = "var seriesService = Resolve<ISeriesService>();\nseriesService.AddSeries((Series)null);",
+            });
+
+            result.ReturnValue.Should().BeNull();
+            result.DebugVariables.Should().BeNull();
+            result.Error.Should().StartWith("Object reference not set to an instance of an object");
+            result.ErrorDiagnostics.Should().NotBeNull();
+            result.ErrorDiagnostics.First().StartLineNumber.Should().Be(1);
+            result.ErrorDiagnostics.First().EndLineNumber.Should().Be(2);
+            result.ErrorDiagnostics.First().EndColumn.Should().Be(38);
+            result.ErrorDiagnostics.First().Message.Should().StartWith("Object reference not set to an instance of an object");
+            result.ErrorDiagnostics.First().FullMessage.Should().StartWith("System.NullReferenceException: Object reference not set to an instance of an object");
+        }
+    }
+}

src/NzbDrone.Integration.Test/Sonarr.Integration.Test.csproj

@@ -9,5 +9,6 @@
   <ItemGroup>
     <ProjectReference Include="..\NzbDrone.Api\Sonarr.Api.csproj" />
     <ProjectReference Include="..\NzbDrone.Test.Common\Sonarr.Test.Common.csproj" />
+    <ProjectReference Include="..\Sonarr.Api.V3\Sonarr.Api.V3.csproj" />
   </ItemGroup>
 </Project>

src/NzbDrone.Test.Common/AutoMoqerContainer.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using NzbDrone.Common.Composition;
+
+namespace NzbDrone.Test.Common
+{
+    public class AutoMoqerContainer : IContainer
+    {
+        private readonly AutoMoq.AutoMoqer _autoMoqer;
+
+        public AutoMoqerContainer(AutoMoq.AutoMoqer autoMoqer)
+        {
+            _autoMoqer = autoMoqer;
+        }
+
+        public IEnumerable<Type> GetImplementations(Type contractType)
+        {
+            throw new NotImplementedException();
+        }
+
+        public bool IsTypeRegistered(Type type)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Register<T>(T instance) where T : class
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Register(Type serviceType, Type implementationType)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Register<TService>(Func<IContainer, TService> factory) where TService : class
+        {
+            throw new NotImplementedException();
+        }
+
+        public void RegisterAllAsSingleton(Type registrationType, IEnumerable<Type> implementationList)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void RegisterSingleton(Type service, Type implementation)
+        {
+            throw new NotImplementedException();
+        }
+
+        public T Resolve<T>() where T : class
+        {
+            return _autoMoqer.Resolve<T>();
+        }
+
+        public object Resolve(Type type)
+        {
+            throw new NotImplementedException();
+        }
+
+        public IEnumerable<T> ResolveAll<T>() where T : class
+        {
+            throw new NotImplementedException();
+        }
+
+        void IContainer.Register<TService, TImplementation>()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/Sonarr.Api.V3/Diagnostics/DiagnosticStatusModule.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Diagnostics;
+using Nancy;
+using NzbDrone.Core.Datastore;
+using NzbDrone.Core.Diagnostics;
+using Sonarr.Api.V3;
+using Sonarr.Http.Extensions;
+
+namespace NzbDrone.Api.V3.Diagnostics
+{
+    public class DiagnosticStatusModule : SonarrV3Module
+    {
+        private readonly IDiagnosticFeatureSwitches _featureSwitches;
+        private readonly IMainDatabase _mainDatabase;
+        private readonly ILogDatabase _logDatabase;
+
+        public DiagnosticStatusModule(IDiagnosticFeatureSwitches featureSwitches,
+                                      IMainDatabase mainDatabase,
+                                      ILogDatabase logDatabase)
+            : base("diagnostic")
+        {
+            _featureSwitches = featureSwitches;
+            _mainDatabase = mainDatabase;
+            _logDatabase = logDatabase;
+
+            Get("/status", x => GetStatus());
+        }
+
+        private object GetStatus()
+        {
+            return new
+            {
+                Process = GetProcessStats(),
+                DatabaseMain = GetDatabaseStats(_mainDatabase),
+                DatabaseLog = GetDatabaseStats(_logDatabase),
+                CommandsExecuted = (long?)null,
+                ScriptConsoleEnabled = _featureSwitches.ScriptConsoleEnabled
+            };
+        }
+
+        private object GetProcessStats()
+        {
+            var process = Process.GetCurrentProcess();
+
+            return new
+            {
+                StartTime = process.StartTime,
+                TotalProcessorTime = process.TotalProcessorTime.TotalMilliseconds,
+                WorkingSet = process.WorkingSet64,
+                VirtualMemorySize = process.VirtualMemorySize64,
+            };
+        }
+
+        private object GetDatabaseStats(IDatabase database)
+        {
+            return new
+            {
+                Size = database.Size,
+                Version = database.Version
+            };
+        }
+    }
+}

src/Sonarr.Api.V3/Diagnostics/ScriptRunnerModule.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Linq;
+using Nancy;
+using Nancy.Extensions;
+using NzbDrone.Core.Diagnostics;
+using Sonarr.Http.Extensions;
+
+namespace Sonarr.Api.V3.Diagnostics
+{
+    public class ScriptRunnerModule : SonarrV3Module
+    {
+        private readonly IDiagnosticScriptRunner _scriptRunner;
+        private readonly IDiagnosticFeatureSwitches _featureSwitches;
+
+        public ScriptRunnerModule(IDiagnosticScriptRunner scriptRunner,
+                                  IDiagnosticFeatureSwitches featureSwitches)
+            : base("diagnostic/script")
+        {
+            _scriptRunner = scriptRunner;
+            _featureSwitches = featureSwitches;
+
+            Post("/validate", x => ValidateScript(x));
+            Post("/execute", x => ExecuteScript(x));
+        }
+
+        private ScriptRequest ParseRequest()
+        {
+            if (Request.Headers.ContentType == "application/json")
+            {
+                return Request.Body.FromJson<ScriptRequest>();
+            }
+            else if (Request.Headers.ContentType == "text/plain")
+            {
+                return new ScriptRequest { Code = Context.Request.Body.AsString() };
+            }
+            else
+            {
+                return Request.Body.FromJson<ScriptRequest>();
+            }
+        }
+
+        public object ValidateScript(dynamic options)
+        {
+            if (!_featureSwitches.ScriptConsoleEnabled)
+            {
+                return new NotFoundResponse();
+            }
+
+            var request = ParseRequest();
+
+            var result = _scriptRunner.Validate(request);
+
+            return new
+            {
+                ErrorDiagnostics = result.Messages?.ToArray()
+            };
+        }
+
+        public object ExecuteScript(dynamic options)
+        {
+            if (!_featureSwitches.ScriptConsoleEnabled)
+            {
+                return new NotFoundResponse();
+            }
+
+            var request = ParseRequest();
+
+            var result = _scriptRunner.Execute(request);
+
+            return new
+            {
+                ResultStateId = result.StateId,
+                ReturnValue = result.ReturnValue,
+                DebugVariables = request.Debug ? result.Variables : null,
+                Error = result.Exception?.Message,
+                ErrorDiagnostics = result.Validation?.Messages?.ToArray()
+            };
+        }
+    }
+}

yarn.lock

@@ -1080,6 +1080,14 @@
     "@types/prop-types" "*"
     csstype "^2.2.0"
 
+"@types/react@^16.x":
+  version "16.9.35"
+  resolved "https://registry.yarnpkg.com/@types/react/-/react-16.9.35.tgz#a0830d172e8aadd9bd41709ba2281a3124bbd368"
+  integrity sha512-q0n0SsWcGc8nDqH2GJfWQWUOmZSJhXV64CjVN5SvcNti3TdEaA3AH0D8DwNmMdzjMAC/78tB8nAZIlV8yTz+zQ==
+  dependencies:
+    "@types/prop-types" "*"
+    csstype "^2.2.0"
+
 "@types/shallowequal@^1.1.1":
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/@types/shallowequal/-/shallowequal-1.1.1.tgz#aad262bb3f2b1257d94c71d545268d592575c9b1"
@@ -5922,6 +5930,11 @@ moment@2.24.0:
   resolved "https://registry.yarnpkg.com/moment/-/moment-2.24.0.tgz#0d055d53f5052aa653c9f6eb68bb5d12bf5c2b5b"
   integrity sha512-bV7f+6l2QigeBBZSM/6yTNq4P2fNpSWj/0e7jQcy87A8e7o2nAfP/34/2ky5Vw4B9S446EtIhodAzkFCcR4dQg==
 
+monaco-editor@*, monaco-editor@0.20.0:
+  version "0.20.0"
+  resolved "https://registry.yarnpkg.com/monaco-editor/-/monaco-editor-0.20.0.tgz#5d5009343a550124426cb4d965a4d27a348b4dea"
+  integrity sha512-hkvf4EtPJRMQlPC3UbMoRs0vTAFAYdzFQ+gpMb8A+9znae1c43q8Mab9iVsgTcg/4PNiLGGn3SlDIa8uvK1FIQ==
+
 mousetrap@1.6.3:
   version "1.6.3"
   resolved "https://registry.yarnpkg.com/mousetrap/-/mousetrap-1.6.3.tgz#80fee49665fd478bccf072c9d46bdf1bfed3558a"
@@ -7381,6 +7394,15 @@ react-measure@1.4.7:
     prop-types "^15.5.4"
     resize-observer-polyfill "^1.4.1"
 
+react-monaco-editor@0.36.0:
+  version "0.36.0"
+  resolved "https://registry.yarnpkg.com/react-monaco-editor/-/react-monaco-editor-0.36.0.tgz#ac085c14f25fb072514c925596f6a06a711ee078"
+  integrity sha512-JVA5SZhOoYZ0DCdTwYgagtRb3jHo4KN7TVFiJauG+ZBAJWfDSTzavPIrwzWbgu8ahhDqDk4jUcYlOJL2BC/0UA==
+  dependencies:
+    "@types/react" "^16.x"
+    monaco-editor "*"
+    prop-types "^15.7.2"
+
 react-popper@1.3.3:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/react-popper/-/react-popper-1.3.3.tgz#2c6cef7515a991256b4f0536cd4bdcb58a7b6af6"