Resolve Editor slowness by replacing Editor React wrapper lib

web/package.json

@@ -37,6 +37,11 @@
     "@blueprintjs/core": "3.26.1",
     "@blueprintjs/datetime": "3.13.0",
     "@blueprintjs/select": "3.12.3",
+    "@codemirror/commands": "^6.2.3",
+    "@codemirror/lang-markdown": "^6.1.1",
+    "@codemirror/language-data": "^6.3.0",
+    "@codemirror/state": "^6.2.0",
+    "@codemirror/view": "^6.9.6",
     "@harness/design-system": "1.4.0",
     "@harness/icons": "1.110.2",
     "@harness/ng-tooltip": ">=1.31.25",
@@ -47,7 +52,7 @@
     "@uiw/codemirror-extensions-color": "^4.19.9",
     "@uiw/codemirror-extensions-hyper-link": "^4.19.9",
     "@uiw/codemirror-themes-all": "^4.19.9",
-    "@uiw/react-markdown-editor": "^5.10.1",
+    "@uiw/react-markdown-preview": "^4.1.12",
     "anser": "2.0.1",
     "classnames": "^2.2.6",
     "clipboard-copy": "^3.1.0",

web/src/App.module.scss

@@ -5,11 +5,6 @@
  */
 
 .main {
-  --code-editor-font-family: ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono',
-    monospace;
-  --code-editor-font-size: 13px;
-  --code-editor-border-color: var(--grey-200);
-
   :global {
     .Resizer {
       background-color: var(--grey-300);

web/src/components/CommentBox/CommentBox.module.scss

@@ -63,8 +63,7 @@
   }
 
   .editCommentContainer {
-    background-color: var(--grey-50) !important;
+    padding: var(--spacing-small) !important;
-    padding: var(--spacing-large) !important;
     border-radius: var(--box-radius);
   }
 

web/src/components/CommentBox/CommentBox.tsx

@@ -1,5 +1,6 @@
 import React, { useCallback, useRef, useState } from 'react'
 import { useResizeDetector } from 'react-resize-detector'
+import type { EditorView } from '@codemirror/view'
 import { Render, Match, Truthy, Falsy, Else } from 'react-jsx-match'
 import { Container, Layout, Avatar, TextInput, Text, Color, FontVariation, FlexExpander } from '@harness/uicore'
 import cx from 'classnames'
@@ -10,10 +11,7 @@ import { ThreadSection } from 'components/ThreadSection/ThreadSection'
 import { PipeSeparator } from 'components/PipeSeparator/PipeSeparator'
 import { useAppContext } from 'AppContext'
 import { OptionsMenuButton } from 'components/OptionsMenuButton/OptionsMenuButton'
-import {
+import { MarkdownEditorWithPreview } from 'components/MarkdownEditorWithPreview/MarkdownEditorWithPreview'
-  MarkdownEditorWithPreview,
-  MarkdownEditorWithPreviewResetProps
-} from 'components/MarkdownEditorWithPreview/MarkdownEditorWithPreview'
 import { MarkdownViewer } from 'components/MarkdownViewer/MarkdownViewer'
 import css from './CommentBox.module.scss'
 
@@ -106,7 +104,7 @@ export const CommentBox = <T = unknown,>({
         .join(CRLF)
     )
   }, [])
-  const editorRef = useRef<MarkdownEditorWithPreviewResetProps>()
+  const viewRef = useRef<EditorView>()
 
   return (
     <Container
@@ -144,11 +142,10 @@ export const CommentBox = <T = unknown,>({
               </Container>
             </Truthy>
             <Falsy>
-              <Container
+              <Container className={cx(css.newCommentContainer, { [css.hasThread]: !!comments.length })}>
-                padding="xlarge"
-                className={cx(css.newCommentContainer, { [css.hasThread]: !!comments.length })}>
                 <MarkdownEditorWithPreview
-                  editorRef={editorRef as React.MutableRefObject<MarkdownEditorWithPreviewResetProps>}
+                  viewRef={viewRef}
+                  noBorder
                   i18n={{
                     placeHolder: getString(comments.length ? 'replyHere' : 'leaveAComment'),
                     tabEdit: getString('write'),
@@ -170,7 +167,13 @@ export const CommentBox = <T = unknown,>({
                         setMarkdown('')
 
                         if (resetOnSave) {
-                          editorRef.current?.resetEditor?.()
+                          viewRef.current?.dispatch({
+                            changes: {
+                              from: 0,
+                              to: viewRef.current.state.doc.length,
+                              insert: ''
+                            }
+                          })
                         } else {
                           setComments([...comments, updatedItem as CommentItem<T>])
                           setShowReplyPlaceHolder(true)

web/src/components/CommitModalButton/CommitModalButton.tsx

@@ -177,7 +177,7 @@ export const CommitModalButton: React.FC<CommitModalButtonProps> = ({
                     disabled={disableBranchCreation}
                     label=""
                     onChange={e => {
-                      setTargetBranchOption(get(e.target, 'defaultValue'))
+                      setTargetBranchOption(get(e.target, 'defaultValue') as unknown as CommitToGitRefOption)
                     }}
                     items={[
                       {

web/src/components/Editor/Editor.module.scss

@@ -0,0 +1,30 @@
+@import 'src/utils/utils';
+
+.editor {
+  :global {
+    .cm-editor {
+      outline: none;
+      border: 1px solid var(--grey-200);
+      border-radius: 4px;
+      min-height: var(--editor-min-height, 60px);
+      max-height: var(--editor-max-height, 600px);
+
+      &.cm-focused {
+        border-color: var(--primary-7);
+        outline: none;
+      }
+
+      .cm-scroller {
+        overflow: auto;
+        padding: var(--spacing-small);
+
+        .cm-line {
+          &,
+          * {
+            @include markdown-font;
+          }
+        }
+      }
+    }
+  }
+}

web/src/components/Editor/Editor.module.scss.d.ts

@@ -0,0 +1,6 @@
+/* eslint-disable */
+// this is an auto-generated file
+declare const styles: {
+  readonly editor: string
+}
+export default styles

web/src/components/Editor/Editor.tsx

@@ -2,41 +2,64 @@ import React, { useEffect, useMemo, useRef } from 'react'
 import { Container } from '@harness/uicore'
 import { LanguageDescription } from '@codemirror/language'
 import { indentWithTab } from '@codemirror/commands'
+import cx from 'classnames'
 import type { ViewUpdate } from '@codemirror/view'
+import type { Text } from '@codemirror/state'
 import { languages } from '@codemirror/language-data'
-import { EditorView, keymap } from '@codemirror/view'
+import { markdown } from '@codemirror/lang-markdown'
-import { noop } from 'lodash-es'
+import { EditorView, keymap, placeholder as placeholderExtension } from '@codemirror/view'
 import { Compartment, EditorState, Extension } from '@codemirror/state'
 import { color } from '@uiw/codemirror-extensions-color'
 import { hyperLink } from '@uiw/codemirror-extensions-hyper-link'
 import { githubLight as theme } from '@uiw/codemirror-themes-all'
+import css from './Editor.module.scss'
 
-interface EditorProps {
+export interface EditorProps {
-  filename: string
+  content: string
-  source: string
+  filename?: string
-  onViewUpdate?: (update: ViewUpdate) => void
+  forMarkdown?: boolean
+  placeholder?: string
   readonly?: boolean
+  autoFocus?: boolean
   className?: string
   extensions?: Extension
+  maxHeight?: string | number
   viewRef?: React.MutableRefObject<EditorView | undefined>
+  setDirty?: React.Dispatch<React.SetStateAction<boolean>>
+  onChange?: (doc: Text, viewUpdate: ViewUpdate) => void
+  onViewUpdate?: (viewUpdate: ViewUpdate) => void
 }
 
 export const Editor = React.memo(function CodeMirrorReactEditor({
-  source,
+  content,
   filename,
-  onViewUpdate = noop,
+  forMarkdown,
+  placeholder,
   readonly = false,
+  autoFocus,
   className,
   extensions = new Compartment().of([]),
-  viewRef
+  maxHeight,
+  viewRef,
+  setDirty,
+  onChange,
+  onViewUpdate
 }: EditorProps) {
   const view = useRef<EditorView>()
   const ref = useRef<HTMLDivElement>()
   const languageConfig = useMemo(() => new Compartment(), [])
+  const markdownLanguageSupport = useMemo(() => markdown({ codeLanguages: languages }), [])
+  const style = useMemo(() => {
+    if (maxHeight) {
+      return {
+        '--editor-max-height': Number.isInteger(maxHeight) ? `${maxHeight}px` : maxHeight
+      } as React.CSSProperties
+    }
+  }, [maxHeight])
 
   useEffect(() => {
     const editorView = new EditorView({
-      doc: source,
+      doc: content,
       extensions: [
         extensions,
 
@@ -45,11 +68,21 @@ export const Editor = React.memo(function CodeMirrorReactEditor({
         theme,
 
         EditorView.lineWrapping,
+
+        ...(placeholder ? [placeholderExtension(placeholder)] : []),
+
         keymap.of([indentWithTab]),
 
         ...(readonly ? [EditorState.readOnly.of(true), EditorView.editable.of(false)] : []),
 
-        EditorView.updateListener.of(onViewUpdate),
+        EditorView.updateListener.of(viewUpdate => {
+          setDirty?.(!cleanDoc.eq(viewUpdate.state.doc))
+          onViewUpdate?.(viewUpdate)
+
+          if (viewUpdate.docChanged) {
+            onChange?.(viewUpdate.state.doc, viewUpdate)
+          }
+        }),
 
         /**
         languageConfig is a compartment that defaults to an empty array (no language support)
@@ -67,25 +100,35 @@ export const Editor = React.memo(function CodeMirrorReactEditor({
       viewRef.current = editorView
     }
 
+    const cleanDoc = editorView.state.doc
+
+    if (autoFocus) {
+      editorView.focus()
+    }
+
     return () => {
       editorView.destroy()
     }
   }, []) // eslint-disable-line react-hooks/exhaustive-deps
 
-  // Dynamically load language support based on filename
+  // Dynamically load language support based on filename. Note that
+  // we need to configure languageSupport for Markdown separately to
+  // enable syntax highlighting for all code blocks (multi-lang).
   useEffect(() => {
-    if (filename) {
+    if (forMarkdown) {
-      languageDescriptionFrom(filename)
+      view.current?.dispatch({ effects: languageConfig.reconfigure(markdownLanguageSupport) })
+    } else if (filename) {
+      LanguageDescription.matchFilename(languages, filename)
         ?.load()
         .then(languageSupport => {
-          view.current?.dispatch({ effects: languageConfig.reconfigure(languageSupport) })
+          view.current?.dispatch({
+            effects: languageConfig.reconfigure(
+              languageSupport.language.name === 'markdown' ? markdownLanguageSupport : languageSupport
+            )
+          })
         })
     }
-  }, [filename, view, languageConfig])
+  }, [filename, forMarkdown, view, languageConfig, markdownLanguageSupport])
 
-  return <Container ref={ref} className={className} />
+  return <Container ref={ref} className={cx(css.editor, className)} style={style} />
 })
-
-function languageDescriptionFrom(filename: string) {
-  return LanguageDescription.matchFilename(languages, filename)
-}

web/src/components/ImageCarousel/ImageCarousel.tsx

@@ -1,20 +1,24 @@
 import React, { useState } from 'react'
 import { ButtonGroup, ButtonVariation, Button, Container, Dialog, Carousel } from '@harness/uicore'
 import { ZOOM_INC_DEC_LEVEL } from 'utils/Utils'
-import type { UseStringsReturn } from 'framework/strings'
 import css from './ImageCarousel.module.scss'
+
 interface ImageCarouselProps {
   isOpen: boolean
   setIsOpen: (value: boolean) => void
   setZoomLevel: (value: number) => void
   zoomLevel: number
   imgEvent: string[]
-  getString: UseStringsReturn['getString']
+  i18n: {
+    zoomIn: string
+    zoomOut: string
+  }
 }
 
 const ImageCarousel = (props: ImageCarouselProps) => {
-  const { getString, isOpen, setIsOpen, setZoomLevel, zoomLevel, imgEvent } = props
+  const { isOpen, setIsOpen, setZoomLevel, zoomLevel, imgEvent, i18n } = props
   const [imgTitle, setImageTitle] = useState(imgEvent[0])
+
   return (
     <Dialog
       portalClassName={css.portalContainer}
@@ -55,7 +59,7 @@ const ImageCarousel = (props: ImageCarouselProps) => {
             variation={ButtonVariation.TERTIARY}
             icon="zoom-in"
             data-testid="zoomInButton"
-            tooltip={getString('zoomIn')}
+            tooltip={i18n.zoomIn}
             onClick={() => {
               Number(zoomLevel.toFixed(1)) < 2 && setZoomLevel(zoomLevel + ZOOM_INC_DEC_LEVEL)
             }}
@@ -71,7 +75,7 @@ const ImageCarousel = (props: ImageCarouselProps) => {
             variation={ButtonVariation.TERTIARY}
             icon="zoom-out"
             data-testid="zoomOutButton"
-            tooltip={getString('zoomOut')}
+            tooltip={i18n.zoomOut}
             onClick={() => {
               Number(zoomLevel.toFixed(1)) > 0.3 && setZoomLevel(zoomLevel - ZOOM_INC_DEC_LEVEL)
             }}
@@ -83,3 +87,6 @@ const ImageCarousel = (props: ImageCarouselProps) => {
 }
 
 export default ImageCarousel
+
+// TODO: Dialog does not have i18n context when mounted inside CommentBox/different React root
+// Hence getString can't get proper translations

web/src/components/MarkdownEditorWithPreview/MarkdownEditorWithPreview.module.scss

@@ -101,12 +101,12 @@
 
   .markdownEditor {
     :global {
-      .cm-editor .cm-line {
+      // .cm-editor .cm-line {
-        &,
+      //   &,
-        * {
+      //   * {
-          @include mono-font;
+      //     @include mono-font;
-        }
+      //   }
-      }
+      // }
 
       .md-editor {
         background-color: transparent !important;
@@ -153,3 +153,99 @@
     }
   }
 }
+
+.container {
+  --tab-border-primary: rgba(176, 177, 195, 0.5);
+  --radius: 5px;
+
+  box-shadow: var(--elevation-2);
+  border-radius: var(--radius);
+  border: 1px solid var(--tab-border-primary);
+  border-bottom: none;
+  background-color: var(--white);
+
+  &.noBorder {
+    border: none;
+    box-shadow: none;
+  }
+
+  position: relative;
+
+  .tabs {
+    list-style: none;
+    margin: 0;
+    padding: 0;
+    display: flex;
+    background-color: var(--grey-100);
+    padding: 15px 15px 0;
+    background: var(--grey-50) !important;
+    border-bottom: 1px solid var(--tab-border-primary);
+    border-top-left-radius: var(--radius);
+    border-top-right-radius: var(--radius);
+
+    li {
+      a {
+        padding: 6px 15px;
+        display: block;
+        font-style: normal;
+        font-weight: 500;
+        font-size: 12px;
+        line-height: 18px;
+        text-decoration: none;
+        color: var(--grey-900);
+
+        position: relative;
+        border: 1px solid transparent;
+        border-bottom: none;
+        border-top-left-radius: var(--radius);
+        border-top-right-radius: var(--radius);
+
+        &::after {
+          content: '';
+          right: 0;
+          left: 0;
+          bottom: -1px;
+          height: 1px;
+          width: 100%;
+          position: absolute;
+          background-color: transparent;
+        }
+
+        &[aria-selected='true'] {
+          background-color: var(--white);
+          border-color: var(--tab-border-primary);
+
+          &::after {
+            background-color: var(--white);
+          }
+        }
+      }
+    }
+  }
+
+  .toolbar {
+    position: absolute;
+    top: 12px;
+    right: 16px;
+    margin: 0;
+    padding: 0;
+    display: flex;
+  }
+
+  .tabContent {
+    padding: var(--spacing-large);
+    background-color: var(--white);
+    border-bottom-left-radius: var(--radius);
+    border-bottom-right-radius: var(--radius);
+  }
+
+  .buttonsBar {
+    padding: 0 var(--spacing-large) var(--spacing-large);
+    background-color: var(--white);
+    border-radius: var(--radius);
+  }
+
+  .hidden {
+    display: none;
+  }
+}

web/src/components/MarkdownEditorWithPreview/MarkdownEditorWithPreview.module.scss.d.ts

@@ -6,5 +6,11 @@ declare const styles: {
   readonly tabs: string
   readonly preview: string
   readonly markdownEditor: string
+  readonly container: string
+  readonly noBorder: string
+  readonly toolbar: string
+  readonly tabContent: string
+  readonly buttonsBar: string
+  readonly hidden: string
 }
 export default styles

web/src/components/MarkdownEditorWithPreview/MarkdownEditorWithPreview.tsx

@@ -1,22 +1,45 @@
-import React, { useEffect, useState } from 'react'
+import React, { useCallback, useEffect, useRef, useState } from 'react'
-import { Button, Container, ButtonVariation, Layout } from '@harness/uicore'
+import { Button, Container, ButtonVariation, Layout, Color, ButtonSize, IconName } from '@harness/uicore'
-import MarkdownEditor from '@uiw/react-markdown-editor'
-import { Tab, Tabs } from '@blueprintjs/core'
-import { indentWithTab } from '@codemirror/commands'
 import cx from 'classnames'
-import { keymap, EditorView } from '@codemirror/view'
+import type { EditorView } from '@codemirror/view'
-import { noop } from 'lodash-es'
+import { EditorSelection } from '@codemirror/state'
-import type { IToolBarProps } from '@uiw/react-markdown-editor/cjs/components/ToolBar'
+import { Editor } from 'components/Editor/Editor'
+import { MarkdownViewer } from 'components/MarkdownViewer/MarkdownViewer'
+import { useStrings } from 'framework/strings'
 import css from './MarkdownEditorWithPreview.module.scss'
 
-export interface MarkdownEditorWithPreviewResetProps {
+enum MarkdownEditorTab {
-  resetEditor: () => void
+  WRITE = 'write',
+  PREVIEW = 'preview'
 }
 
+enum ToolbarAction {
+  HEADER = 'HEADER',
+  BOLD = 'BOLD',
+  ITALIC = 'ITALIC',
+  UNORDER_LIST = 'UNORDER_LIST',
+  CHECK_LIST = 'CHECK_LIST',
+  CODE_BLOCK = 'CODE_BLOCK'
+}
+
+interface ToolbarItem {
+  icon: IconName
+  action: ToolbarAction
+}
+
+const toolbar: ToolbarItem[] = [
+  { icon: 'header', action: ToolbarAction.HEADER },
+  { icon: 'bold', action: ToolbarAction.BOLD },
+  { icon: 'italic', action: ToolbarAction.ITALIC },
+  { icon: 'properties', action: ToolbarAction.UNORDER_LIST },
+  { icon: 'form', action: ToolbarAction.CHECK_LIST },
+  { icon: 'main-code-yaml', action: ToolbarAction.CODE_BLOCK }
+]
+
 interface MarkdownEditorWithPreviewProps {
-  value: string
+  value?: string
-  onChange?: (value: string, original: string) => void
+  onChange?: (value: string) => void
-  onSave?: (value: string, original: string) => void
+  onSave?: (value: string) => void
   onCancel?: () => void
   i18n: {
     placeHolder: string
@@ -28,114 +51,220 @@ interface MarkdownEditorWithPreviewProps {
   hideButtons?: boolean
   hideCancel?: boolean
   editorHeight?: string
-  maxEditorHeight?: string
+  noBorder?: boolean
-  editorRef?: React.MutableRefObject<MarkdownEditorWithPreviewResetProps>
+  viewRef?: React.MutableRefObject<EditorView | undefined>
 }
 
 export function MarkdownEditorWithPreview({
-  value,
+  value = '',
-  onChange = noop,
+  onChange,
-  onSave = noop,
+  onSave,
-  onCancel = noop,
+  onCancel,
   i18n,
   hideButtons,
   hideCancel,
   editorHeight,
-  maxEditorHeight,
+  noBorder,
-  editorRef
+  viewRef: viewRefProp
 }: MarkdownEditorWithPreviewProps) {
-  const [original, setOriginal] = useState(value)
+  const [selectedTab, setSelectedTab] = useState(MarkdownEditorTab.WRITE)
-  const [selectedTab, setSelectedTab] = useState<MarkdownEditorTab>(MarkdownEditorTab.WRITE)
+  const viewRef = useRef<EditorView>()
-  const [val, setVal] = useState(value)
+  const [dirty, setDirty] = useState(false)
+  const { getString } = useStrings()
+  const onToolbarAction = useCallback((action: ToolbarAction) => {
+    const view = viewRef.current
+
+    if (!view?.state) {
+      return
+    }
+
+    // Note: Part of this code is copied from @uiwjs/react-markdown-editor
+    // MIT License, Copyright (c) 2020 uiw
+    // @see https://github.dev/uiwjs/react-markdown-editor/blob/2d3f45079c79616b867ef03681a8ba9799169921/src/commands/header.tsx
+    switch (action) {
+      case ToolbarAction.HEADER: {
+        const lineInfo = view.state.doc.lineAt(view.state.selection.main.from)
+        let mark = '#'
+        const matchMark = lineInfo.text.match(/^#+/)
+        if (matchMark && matchMark[0]) {
+          const txt = matchMark[0]
+          if (txt.length < 6) {
+            mark = txt + '#'
+          }
+        }
+        if (mark.length > 6) {
+          mark = '#'
+        }
+        const title = lineInfo.text.replace(/^#+/, '')
+        view.dispatch({
+          changes: {
+            from: lineInfo.from,
+            to: lineInfo.to,
+            insert: `${mark} ${title}`
+          },
+          // selection: EditorSelection.range(lineInfo.from + mark.length, lineInfo.to),
+          selection: { anchor: lineInfo.from + mark.length + 1 }
+        })
+        break
+      }
+
+      case ToolbarAction.BOLD: {
+        view.dispatch(
+          view.state.changeByRange(range => ({
+            changes: [
+              { from: range.from, insert: '**' },
+              { from: range.to, insert: '**' }
+            ],
+            range: EditorSelection.range(range.from + 2, range.to + 2)
+          }))
+        )
+        break
+      }
+
+      case ToolbarAction.ITALIC: {
+        view.dispatch(
+          view.state.changeByRange(range => ({
+            changes: [
+              { from: range.from, insert: '*' },
+              { from: range.to, insert: '*' }
+            ],
+            range: EditorSelection.range(range.from + 1, range.to + 1)
+          }))
+        )
+        break
+      }
+
+      case ToolbarAction.UNORDER_LIST: {
+        const lineInfo = view.state.doc.lineAt(view.state.selection.main.from)
+        let mark = '- '
+        const matchMark = lineInfo.text.match(/^-/)
+        if (matchMark && matchMark[0]) {
+          mark = ''
+        }
+        view.dispatch({
+          changes: {
+            from: lineInfo.from,
+            to: lineInfo.to,
+            insert: `${mark}${lineInfo.text}`
+          },
+          // selection: EditorSelection.range(lineInfo.from + mark.length, lineInfo.to),
+          selection: { anchor: view.state.selection.main.from + mark.length }
+        })
+        break
+      }
+
+      case ToolbarAction.CHECK_LIST: {
+        const lineInfo = view.state.doc.lineAt(view.state.selection.main.from)
+        let mark = '- [ ]  '
+        const matchMark = lineInfo.text.match(/^-\s\[\s\]\s/)
+        if (matchMark && matchMark[0]) {
+          mark = ''
+        }
+        view.dispatch({
+          changes: {
+            from: lineInfo.from,
+            to: lineInfo.to,
+            insert: `${mark}${lineInfo.text}`
+          },
+          // selection: EditorSelection.range(lineInfo.from + mark.length, lineInfo.to),
+          selection: { anchor: view.state.selection.main.from + mark.length }
+        })
+        break
+      }
+
+      case ToolbarAction.CODE_BLOCK: {
+        const main = view.state.selection.main
+        const txt = view.state.sliceDoc(view.state.selection.main.from, view.state.selection.main.to)
+        view.dispatch({
+          changes: {
+            from: main.from,
+            to: main.to,
+            insert: `\`\`\`tsx\n${txt}\n\`\`\``
+          },
+          selection: EditorSelection.range(main.from + 3, main.from + 6)
+        })
+        break
+      }
+    }
+  }, [])
 
   useEffect(() => {
-    if (editorRef) {
+    if (viewRefProp) {
-      editorRef.current = {
+      viewRefProp.current = viewRef.current
-        resetEditor: () => {
-          setOriginal(value)
-          setVal(value)
-        }
-      }
-      editorRef.current.resetEditor()
     }
-  }, [editorRef]) // eslint-disable-line react-hooks/exhaustive-deps
+  }, [viewRefProp, viewRef.current]) // eslint-disable-line react-hooks/exhaustive-deps
 
   return (
-    <Container className={cx(css.main, selectedTab === MarkdownEditorTab.PREVIEW ? css.withPreview : '')}>
+    <Container className={cx(css.container, { [css.noBorder]: noBorder })}>
-      <Layout.Vertical spacing="large">
+      <ul className={css.tabs}>
-        <Tabs
+        <li>
-          className={css.tabs}
+          <a
-          defaultSelectedTabId={selectedTab}
+            role="tab"
-          onChange={tabId => setSelectedTab(tabId as MarkdownEditorTab)}>
+            tabIndex={0}
-          <Tab
+            aria-selected={selectedTab === MarkdownEditorTab.WRITE}
-            id={MarkdownEditorTab.WRITE}
+            onClick={() => setSelectedTab(MarkdownEditorTab.WRITE)}>
-            title={i18n.tabEdit}
+            Write
-            panel={
+          </a>
-              <Container
+        </li>
-                className={css.markdownEditor}
+
-                style={
+        <li>
-                  {
+          <a
-                    '--editor-height': editorHeight,
+            role="tab"
-                    '--max-editor-height': maxEditorHeight
+            tabIndex={0}
-                  } as React.CSSProperties
+            aria-selected={selectedTab === MarkdownEditorTab.PREVIEW}
-                }>
+            onClick={() => setSelectedTab(MarkdownEditorTab.PREVIEW)}>
-                <MarkdownEditor
+            Preview
-                  value={val}
+          </a>
-                  visible={false}
+        </li>
-                  placeholder={i18n.placeHolder}
+      </ul>
-                  theme="light"
+      <Container className={css.toolbar}>
-                  indentWithTab={false}
+        {toolbar.map((item, index) => {
-                  autoFocus
+          return (
-                  // TODO: Customize toolbars to show tooltip.
+            <Button
-                  // @see https://github.com/uiwjs/react-markdown-editor#custom-toolbars
+              key={index}
-                  toolbars={toolbars}
+              size={ButtonSize.SMALL}
-                  toolbarsMode={[]}
+              variation={ButtonVariation.ICON}
-                  basicSetup={{
+              icon={item.icon}
-                    lineNumbers: false,
+              withoutCurrentColor
-                    foldGutter: false,
+              iconProps={{ color: Color.PRIMARY_10, size: 14 }}
-                    highlightActiveLine: false
+              onClick={() => onToolbarAction(item.action)}
-                  }}
+            />
-                  extensions={[keymap.of([indentWithTab]), EditorView.lineWrapping]}
+          )
-                  onChange={(_value, _viewUpdate) => {
+        })}
-                    setVal(_value)
+      </Container>
-                    onChange(_value, original)
+      <Container className={css.tabContent}>
-                  }}
+        <Editor
-                />
+          forMarkdown
-              </Container>
+          content={value || ''}
+          placeholder={i18n.placeHolder}
+          autoFocus
+          viewRef={viewRef}
+          setDirty={setDirty}
+          maxHeight={editorHeight}
+          className={selectedTab === MarkdownEditorTab.PREVIEW ? css.hidden : undefined}
+          onChange={doc => {
+            if (dirty) {
+              onChange?.(doc.toString())
             }
-          />
+          }}
-          <Tab
+        />
-            id={MarkdownEditorTab.PREVIEW}
+        {selectedTab === MarkdownEditorTab.PREVIEW && (
-            disabled={!val}
+          <MarkdownViewer source={viewRef.current?.state.doc.toString() || ''} getString={getString} maxHeight={800} />
-            title={i18n.tabPreview}
-            panel={
-              <Container padding="large" className={css.preview}>
-                <MarkdownEditor.Markdown source={val} />
-              </Container>
-            }
-          />
-        </Tabs>
-        {!hideButtons && (
-          <Container>
-            <Layout.Horizontal spacing="small">
-              <Button
-                disabled={!(val || '').trim() || val === original}
-                variation={ButtonVariation.PRIMARY}
-                onClick={() => onSave(val, original)}
-                text={i18n.save}
-              />
-              {!hideCancel && <Button variation={ButtonVariation.TERTIARY} onClick={onCancel} text={i18n.cancel} />}
-            </Layout.Horizontal>
-          </Container>
         )}
-      </Layout.Vertical>
+      </Container>
+      {!hideButtons && (
+        <Container className={css.buttonsBar}>
+          <Layout.Horizontal spacing="small">
+            <Button
+              disabled={!dirty}
+              variation={ButtonVariation.PRIMARY}
+              onClick={() => onSave?.(viewRef.current?.state.doc.toString() || '')}
+              text={i18n.save}
+            />
+            {!hideCancel && <Button variation={ButtonVariation.TERTIARY} onClick={onCancel} text={i18n.cancel} />}
+          </Layout.Horizontal>
+        </Container>
+      )}
     </Container>
   )
 }
-
-const toolbars: IToolBarProps['toolbars'] = ['bold', 'strike', 'olist', 'ulist', 'todo', 'link', 'image']
-
-enum MarkdownEditorTab {
-  WRITE = 'write',
-  PREVIEW = 'preview'
-}

web/src/components/MarkdownViewer/MarkdownViewer.module.scss

@@ -1,8 +1,14 @@
 .main {
+  overflow: auto;
+
   :global {
     .wmde-markdown {
       pre {
         position: relative;
+
+        .code-line {
+          white-space: break-spaces;
+        }
       }
 
       // Customize https://wangchujiang.com/rehype-video/

web/src/components/MarkdownViewer/MarkdownViewer.tsx

@@ -1,7 +1,8 @@
 import { useHistory } from 'react-router-dom'
 import React, { useCallback, useState } from 'react'
 import { Container } from '@harness/uicore'
-import MarkdownEditor from '@uiw/react-markdown-editor'
+import cx from 'classnames'
+import MarkdownPreview from '@uiw/react-markdown-preview'
 import rehypeVideo from 'rehype-video'
 import rehypeExternalLinks from 'rehype-external-links'
 import { INITIAL_ZOOM_LEVEL } from 'utils/Utils'
@@ -12,9 +13,11 @@ import css from './MarkdownViewer.module.scss'
 interface MarkdownViewerProps {
   source: string
   getString: UseStringsReturn['getString']
+  className?: string
+  maxHeight?: string | number
 }
 
-export function MarkdownViewer({ source, getString }: MarkdownViewerProps) {
+export function MarkdownViewer({ source, getString, className, maxHeight }: MarkdownViewerProps) {
   const [isOpen, setIsOpen] = useState<boolean>(false)
   const history = useHistory()
   const [zoomLevel, setZoomLevel] = useState(INITIAL_ZOOM_LEVEL)
@@ -57,8 +60,11 @@ export function MarkdownViewer({ source, getString }: MarkdownViewerProps) {
   )
 
   return (
-    <Container className={css.main} onClick={interceptClickEventOnViewerContainer}>
+    <Container
-      <MarkdownEditor.Markdown
+      className={cx(css.main, className)}
+      onClick={interceptClickEventOnViewerContainer}
+      style={{ maxHeight: maxHeight }}>
+      <MarkdownPreview
         source={source}
         skipHtml={true}
         warpperElement={{ 'data-color-mode': 'light' }}
@@ -80,7 +86,10 @@ export function MarkdownViewer({ source, getString }: MarkdownViewerProps) {
         setZoomLevel={setZoomLevel}
         zoomLevel={zoomLevel}
         imgEvent={imgEvent}
-        getString={getString}
+        i18n={{
+          zoomIn: getString('zoomIn'),
+          zoomOut: getString('zoomOut')
+        }}
       />
     </Container>
   )

web/src/components/OptionsMenuButton/OptionsMenuButton.tsx

@@ -50,7 +50,12 @@ export const OptionsMenuButton = ({
                     [css.danger]: (item as OptionsMenuItem).isDanger,
                     [css.isDark]: isDark
                   })}
-                  {...omit(item as IMenuItemProps & React.AnchorHTMLAttributes<HTMLAnchorElement>, 'isDanger')}
+                  {...omit(
+                    item as IMenuItemProps & React.AnchorHTMLAttributes<HTMLAnchorElement>,
+                    'isDanger',
+                    'hasIcon',
+                    'iconName'
+                  )}
                 />
               )
           )}

web/src/pages/PullRequest/Conversation/DescriptionBox.tsx

@@ -28,8 +28,8 @@ export const DescriptionBox: React.FC<ConversationProps> = ({
   })
 
   return (
-    <Container className={cx(css.box, css.desc)}>
+    <Container className={cx({ [css.box]: !edit, [css.desc]: !edit })}>
-      <Container padding={{ left: 'small', bottom: 'small' }}>
+      <Container padding={!edit ? { left: 'small', bottom: 'small' } : undefined}>
         {(edit && (
           <MarkdownEditorWithPreview
             value={content}
@@ -59,7 +59,7 @@ export const DescriptionBox: React.FC<ConversationProps> = ({
               save: getString('save'),
               cancel: getString('cancel')
             }}
-            maxEditorHeight="400px"
+            editorHeight="400px"
           />
         )) || (
           <Container className={css.mdWrapper}>

web/src/pages/Repository/RepositoryContent/FileContent/GitBlame.module.scss

@@ -27,6 +27,8 @@
 }
 
 .gitBlame {
+  --code-editor-border-color: var(--grey-200);
+
   padding: 0 var(--spacing-xlarge) 0 var(--spacing-small) !important;
 
   :global {

web/src/pages/Repository/RepositoryContent/FileContent/GitBlame.tsx

@@ -235,7 +235,7 @@ const GitBlameRenderer = React.memo(function GitBlameSourceViewer({
     <Editor
       viewRef={viewRef}
       filename={filename}
-      source={source}
+      content={source}
       readonly={true}
       className={css.main}
       onViewUpdate={onViewUpdate}

web/src/pages/RepositorySettings/GeneralSettingsContent/GeneralSettingsContent.tsx

@@ -73,7 +73,7 @@ const GeneralSettingsContent = (props: GeneralSettingsProps) => {
           showSuccess(getString('repoDeleted', { repo: repoMetadata?.uid }), 5000)
           history.push(routes.toCODERepositories({ space }))
         })
-        .catch((error: any) => {
+        .catch((error: Unknown) => {
           showError(getErrorMessage(error), 0, 'failedToDeleteBranch')
         })
     }
@@ -172,7 +172,6 @@ const GeneralSettingsContent = (props: GeneralSettingsProps) => {
                           setEditDesc(ACCESS_MODES.EDIT)
                         }}
                         {...permissionProps(permEditResult, standalone)}
-
                       />
                     </Text>
                   )}
@@ -191,8 +190,7 @@ const GeneralSettingsContent = (props: GeneralSettingsProps) => {
                   }}
                   variation={ButtonVariation.SECONDARY}
                   text={getString('delete')}
-                  {...permissionProps(permDeleteResult, standalone)}
+                  {...permissionProps(permDeleteResult, standalone)}></Button>
-                  ></Button>
               </Container>
             </Container>
           </Layout.Vertical>

web/src/utils/utils.scss

@@ -1,4 +1,15 @@
+$code-editor-font-family: ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono',
+  monospace;
+
 @mixin mono-font {
-  font-family: var(--code-editor-font-family) !important;
+  font-family: var(--font-family-mono) !important;
-  font-size: var(--code-editor-font-size) !important;
+  font-size: 12px !important;
+  font-feature-settings: 'liga' 0, 'calt' 0;
+  line-height: 18px;
+  letter-spacing: 0px;
+}
+
+@mixin markdown-font {
+  font-family: var(--font-family) !important;
+  font-size: 12px !important;
 }