refactor: move frontmatter parser into commons package

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

commons/package.json

@@ -41,6 +41,7 @@
     "domhandler": "5.0.3",
     "eventemitter2": "6.4.9",
     "isomorphic-ws": "5.0.0",
+    "joi": "17.9.2",
     "reveal.js": "4.5.0",
     "ws": "8.13.0",
     "yjs": "13.6.1"

commons/src/index.ts

@@ -26,11 +26,17 @@ export { waitForOtherPromisesToFinish } from './utils/wait-for-other-promises-to
 
 export { RealtimeDoc } from './y-doc-sync/realtime-doc.js'
 
-export * from './title-extraction/frontmatter-extractor/extractor.js'
-export * from './title-extraction/frontmatter-extractor/types.js'
+export * from './frontmatter-extractor/extractor.js'
+export * from './frontmatter-extractor/types.js'
+export * from './note-frontmatter-parser/parse-raw-frontmatter-from-yaml.js'
+export * from './note-frontmatter-parser/convert-raw-frontmatter-to-note-frontmatter.js'
+export * from './note-frontmatter-parser/default-values.js'
+export * from './note-frontmatter-parser/parse-tags.js'
+export * from './note-frontmatter-parser/types.js'
+
 export * from './title-extraction/generate-note-title.js'
-export * from './title-extraction/types/iso6391.js'
-export * from './title-extraction/types/frontmatter.js'
-export * from './title-extraction/types/slide-show-options.js'
+export * from './note-frontmatter/iso6391.js'
+export * from './note-frontmatter/frontmatter.js'
+export * from './note-frontmatter/slide-show-options.js'
 
 export { extractFirstHeading } from './title-extraction/extract-first-heading.js'

commons/src/note-frontmatter-parser/convert-raw-frontmatter-to-note-frontmatter.spec.ts

@@ -0,0 +1,51 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  NoteFrontmatter,
+  NoteTextDirection,
+  NoteType,
+  OpenGraph
+} from '../note-frontmatter/frontmatter.js'
+import { SlideOptions } from '../note-frontmatter/slide-show-options.js'
+import { convertRawFrontmatterToNoteFrontmatter } from './convert-raw-frontmatter-to-note-frontmatter.js'
+import { describe, expect, it } from '@jest/globals'
+
+describe('convertRawFrontmatterToNoteFrontmatter', () => {
+  it.each([false, true])(
+    'returns the correct note frontmatter with `breaks: %s`',
+    (breaks) => {
+      const slideOptions: SlideOptions = {}
+      const opengraph: OpenGraph = {}
+      expect(
+        convertRawFrontmatterToNoteFrontmatter({
+          title: 'title',
+          description: 'description',
+          robots: 'robots',
+          lang: 'de',
+          type: NoteType.DOCUMENT,
+          dir: NoteTextDirection.LTR,
+          license: 'license',
+          breaks: breaks,
+          opengraph: opengraph,
+          slideOptions: slideOptions,
+          tags: 'tags'
+        })
+      ).toStrictEqual({
+        title: 'title',
+        description: 'description',
+        robots: 'robots',
+        newlinesAreBreaks: breaks,
+        lang: 'de',
+        type: NoteType.DOCUMENT,
+        dir: NoteTextDirection.LTR,
+        opengraph: opengraph,
+        slideOptions: slideOptions,
+        license: 'license',
+        tags: ['tags']
+      } as NoteFrontmatter)
+    }
+  )
+})

commons/src/note-frontmatter-parser/convert-raw-frontmatter-to-note-frontmatter.ts

@@ -0,0 +1,30 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { NoteFrontmatter } from '../note-frontmatter/frontmatter.js'
+import { parseTags } from './parse-tags.js'
+import { RawNoteFrontmatter } from './types.js'
+
+/**
+ * Creates a new frontmatter metadata instance based on the given raw metadata properties.
+ * @param rawData A {@link RawNoteFrontmatter} object containing the properties of the parsed yaml frontmatter.
+ */
+export const convertRawFrontmatterToNoteFrontmatter = (
+  rawData: RawNoteFrontmatter
+): NoteFrontmatter => {
+  return {
+    title: rawData.title,
+    description: rawData.description,
+    robots: rawData.robots,
+    newlinesAreBreaks: rawData.breaks,
+    lang: rawData.lang,
+    type: rawData.type,
+    dir: rawData.dir,
+    opengraph: rawData.opengraph,
+    slideOptions: rawData.slideOptions,
+    license: rawData.license,
+    tags: parseTags(rawData.tags)
+  }
+}

commons/src/note-frontmatter-parser/default-values.ts

@@ -0,0 +1,33 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  NoteFrontmatter,
+  NoteTextDirection,
+  NoteType
+} from '../note-frontmatter/frontmatter.js'
+import { SlideOptions } from '../note-frontmatter/slide-show-options.js'
+
+export const defaultSlideOptions: SlideOptions = {
+  transition: 'zoom',
+  autoSlide: 0,
+  autoSlideStoppable: true,
+  backgroundTransition: 'fade',
+  slideNumber: false
+}
+
+export const defaultNoteFrontmatter: NoteFrontmatter = {
+  title: '',
+  description: '',
+  tags: [],
+  robots: '',
+  lang: 'en',
+  dir: NoteTextDirection.LTR,
+  newlinesAreBreaks: true,
+  license: '',
+  type: NoteType.DOCUMENT,
+  opengraph: {},
+  slideOptions: defaultSlideOptions
+}

commons/src/note-frontmatter-parser/parse-raw-frontmatter-from-yaml.spec.ts

@@ -0,0 +1,76 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { parseRawFrontmatterFromYaml } from './parse-raw-frontmatter-from-yaml.js'
+import { describe, expect, it } from '@jest/globals'
+
+describe('yaml frontmatter', () => {
+  it('should parse "title"', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml('title: test')
+    expect(noteFrontmatter.value?.title).toEqual('test')
+  })
+
+  it('should parse "robots"', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml('robots: index, follow')
+    expect(noteFrontmatter.value?.robots).toEqual('index, follow')
+  })
+
+  it('should parse the deprecated tags syntax', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml('tags: test123, abc')
+    expect(noteFrontmatter.value?.tags).toEqual('test123, abc')
+  })
+
+  it('should parse the tags list syntax', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml(`tags:
+      - test123
+      - abc
+    `)
+    expect(noteFrontmatter.value?.tags).toEqual(['test123', 'abc'])
+  })
+
+  it('should parse the tag inline-list syntax', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml(
+      "tags: ['test123', 'abc']"
+    )
+    expect(noteFrontmatter.value?.tags).toEqual(['test123', 'abc'])
+  })
+
+  it('should parse "breaks"', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml('breaks: false')
+    expect(noteFrontmatter.value?.breaks).toEqual(false)
+  })
+
+  it('should parse an opengraph title', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml(`opengraph:
+      title: Testtitle
+    `)
+    expect(noteFrontmatter.value?.opengraph.title).toEqual('Testtitle')
+  })
+
+  it('should parse multiple opengraph values', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml(`opengraph:
+      title: Testtitle
+      image: https://dummyimage.com/48.png
+      image:type: image/png
+    `)
+    expect(noteFrontmatter.value?.opengraph.title).toEqual('Testtitle')
+    expect(noteFrontmatter.value?.opengraph.image).toEqual(
+      'https://dummyimage.com/48.png'
+    )
+    expect(noteFrontmatter.value?.opengraph['image:type']).toEqual('image/png')
+  })
+
+  it('allows unknown additional options', () => {
+    const noteFrontmatter = parseRawFrontmatterFromYaml(`title: title
+additonal: "additonal"`)
+
+    expect(noteFrontmatter.value?.title).toBe('title')
+  })
+
+  it('throws an error if the yaml is invalid', () => {
+    const a = parseRawFrontmatterFromYaml('A: asd\n  B: asd')
+    expect(a.error?.message).toStrictEqual('Invalid YAML')
+  })
+})

commons/src/note-frontmatter-parser/parse-raw-frontmatter-from-yaml.ts

@@ -0,0 +1,94 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  NoteTextDirection,
+  NoteType,
+  OpenGraph
+} from '../note-frontmatter/frontmatter.js'
+import { ISO6391 } from '../note-frontmatter/iso6391.js'
+import { SlideOptions } from '../note-frontmatter/slide-show-options.js'
+import { defaultNoteFrontmatter } from './default-values.js'
+import type { RawNoteFrontmatter } from './types.js'
+import type { ValidationError } from 'joi'
+import Joi from 'joi'
+import { load } from 'js-yaml'
+
+const schema = Joi.object<RawNoteFrontmatter>({
+  title: Joi.string().optional().default(defaultNoteFrontmatter.title),
+  description: Joi.string()
+    .optional()
+    .default(defaultNoteFrontmatter.description),
+  tags: Joi.alternatives(
+    Joi.array().items(Joi.string()),
+    Joi.string(),
+    Joi.number().cast('string')
+  )
+    .optional()
+    .default(defaultNoteFrontmatter.tags),
+  robots: Joi.string().optional().default(defaultNoteFrontmatter.robots),
+  lang: Joi.string()
+    .valid(...ISO6391)
+    .optional()
+    .default(defaultNoteFrontmatter.lang),
+  dir: Joi.string()
+    .valid(...Object.values(NoteTextDirection))
+    .optional()
+    .default(defaultNoteFrontmatter.dir),
+  breaks: Joi.boolean()
+    .optional()
+    .default(defaultNoteFrontmatter.newlinesAreBreaks),
+  license: Joi.string().optional().default(defaultNoteFrontmatter.license),
+  type: Joi.string()
+    .valid(...Object.values(NoteType))
+    .optional()
+    .default(defaultNoteFrontmatter.type),
+  slideOptions: Joi.object<SlideOptions>({
+    autoSlide: Joi.number().optional(),
+    transition: Joi.string().optional(),
+    backgroundTransition: Joi.string().optional(),
+    autoSlideStoppable: Joi.boolean().optional(),
+    slideNumber: Joi.boolean().optional()
+  })
+    .optional()
+    .default(defaultNoteFrontmatter.slideOptions),
+  opengraph: Joi.object<OpenGraph>({
+    title: Joi.string().optional(),
+    image: Joi.string().uri().optional()
+  })
+    .unknown(true)
+    .optional()
+    .default(defaultNoteFrontmatter.opengraph)
+})
+  .default(defaultNoteFrontmatter)
+  .unknown(true)
+
+const loadYaml = (rawYaml: string): unknown => {
+  try {
+    return load(rawYaml)
+  } catch {
+    return undefined
+  }
+}
+
+type ParserResult =
+  | {
+      error: undefined
+      warning?: ValidationError
+      value: RawNoteFrontmatter
+    }
+  | {
+      error: Error
+      warning?: ValidationError
+      value: undefined
+    }
+
+export const parseRawFrontmatterFromYaml = (rawYaml: string): ParserResult => {
+  const rawNoteFrontmatter = loadYaml(rawYaml)
+  if (rawNoteFrontmatter === undefined) {
+    return { error: new Error('Invalid YAML'), value: undefined }
+  }
+  return schema.validate(rawNoteFrontmatter, { convert: true })
+}

commons/src/note-frontmatter-parser/parse-tags.spec.ts

@@ -0,0 +1,31 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { parseTags } from './parse-tags.js'
+import { expect, it, describe } from '@jest/globals'
+
+describe('parse tags', () => {
+  it('converts comma separated string tags into string list', () => {
+    expect(parseTags('a,b,c,d,e,f')).toStrictEqual([
+      'a',
+      'b',
+      'c',
+      'd',
+      'e',
+      'f'
+    ])
+  })
+
+  it('accepts a string list as tags', () => {
+    expect(parseTags(['a', 'b', ' c', 'd ', 'e', 'f'])).toStrictEqual([
+      'a',
+      'b',
+      'c',
+      'd',
+      'e',
+      'f'
+    ])
+  })
+})

commons/src/note-frontmatter-parser/parse-tags.ts

@@ -0,0 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/**
+ * Parses the given value as tags array.
+ *
+ * @param rawTags The raw value to parse
+ * @return the parsed tags
+ */
+export const parseTags = (rawTags: string | string[]): string[] => {
+  return (Array.isArray(rawTags) ? rawTags : rawTags.split(','))
+    .map((entry) => entry.trim())
+    .filter((tag) => !!tag)
+}

commons/src/note-frontmatter-parser/types.ts

@@ -0,0 +1,26 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  Iso6391Language,
+  NoteTextDirection,
+  NoteType,
+  OpenGraph
+} from '../note-frontmatter/frontmatter.js'
+import { SlideOptions } from '../note-frontmatter/slide-show-options.js'
+
+export interface RawNoteFrontmatter {
+  title: string
+  description: string
+  tags: string | string[]
+  robots: string
+  lang: Iso6391Language
+  dir: NoteTextDirection
+  breaks: boolean
+  license: string
+  type: NoteType
+  slideOptions: SlideOptions
+  opengraph: OpenGraph
+}

commons/src/note-frontmatter/frontmatter.ts

@@ -16,7 +16,7 @@ export enum NoteTextDirection {
 }
 
 export enum NoteType {
-  DOCUMENT = '',
+  DOCUMENT = 'document',
   SLIDE = 'slide'
 }
 export interface NoteFrontmatter {

commons/src/note-frontmatter/iso6391.ts

@@ -28,6 +28,7 @@ export const ISO6391 = [
   'ar-ye',
   'as',
   'ay',
+  'de',
   'de-at',
   'de-ch',
   'de-li',

commons/src/note-frontmatter/slide-show-options.ts

@@ -12,4 +12,4 @@ type WantedRevealOptions =
   | 'backgroundTransition'
   | 'slideNumber'
 
-export type SlideOptions = Required<Pick<RevealOptions, WantedRevealOptions>>
+export type SlideOptions = Pick<RevealOptions, WantedRevealOptions>

commons/src/title-extraction/generate-note-title.spec.ts

@@ -3,9 +3,12 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
+import {
+  NoteFrontmatter,
+  NoteTextDirection,
+  NoteType
+} from '../note-frontmatter/frontmatter.js'
 import { generateNoteTitle } from './generate-note-title.js'
-import { NoteFrontmatter, NoteTextDirection } from './types/frontmatter.js'
-import { NoteType } from './types/frontmatter.js'
 import { describe, expect, it } from '@jest/globals'
 
 const testFrontmatter: NoteFrontmatter = {
@@ -36,7 +39,7 @@ describe('generate note title', () => {
         title: 'frontmatter',
         opengraph: { title: 'opengraph' }
       },
-      'first-heading'
+      () => 'first-heading'
     )
     expect(actual).toEqual('frontmatter')
   })
@@ -44,13 +47,16 @@ describe('generate note title', () => {
   it('will choose the opengraph title second', () => {
     const actual = generateNoteTitle(
       { ...testFrontmatter, opengraph: { title: 'opengraph' } },
-      'first-heading'
+      () => 'first-heading'
     )
     expect(actual).toEqual('opengraph')
   })
 
   it('will choose the first heading third', () => {
-    const actual = generateNoteTitle({ ...testFrontmatter }, 'first-heading')
+    const actual = generateNoteTitle(
+      { ...testFrontmatter },
+      () => 'first-heading'
+    )
     expect(actual).toEqual('first-heading')
   })
 })

commons/src/title-extraction/generate-note-title.ts

@@ -3,28 +3,24 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { NoteFrontmatter } from './types/frontmatter.js'
+import type { NoteFrontmatter } from '../note-frontmatter/frontmatter.js'
 
 /**
  * Generates the note title from the given frontmatter or the first heading in the markdown content.
  *
  * @param frontmatter The frontmatter of the note
- * @param firstHeading The first heading in the markdown content
+ * @param firstHeadingProvider A function that provides the first heading of the markdown content
  * @return The title from the frontmatter or, if no title is present in the frontmatter, the first heading.
  */
 export const generateNoteTitle = (
-  frontmatter: NoteFrontmatter,
-  firstHeading?: string
+  frontmatter: NoteFrontmatter | undefined,
+  firstHeadingProvider: () => string | undefined
 ): string => {
-  if (frontmatter?.title && frontmatter?.title !== '') {
+  if (frontmatter?.title) {
     return frontmatter.title.trim()
-  } else if (
-    frontmatter?.opengraph &&
-    frontmatter?.opengraph.title !== undefined &&
-    frontmatter?.opengraph.title !== ''
-  ) {
-    return (frontmatter?.opengraph.title ?? firstHeading ?? '').trim()
+  } else if (frontmatter?.opengraph.title) {
+    return (frontmatter?.opengraph.title ?? firstHeadingProvider() ?? '').trim()
   } else {
-    return (firstHeading ?? '').trim()
+    return (firstHeadingProvider() ?? '').trim()
   }
 }

frontend/src/components/editor-page/editor-pane/linter/frontmatter-linter.ts

@@ -3,13 +3,11 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { RawNoteFrontmatter } from '../../../../redux/note-details/raw-note-frontmatter-parser/types'
 import type { Linter } from './linter'
 import type { Diagnostic } from '@codemirror/lint'
 import type { EditorView } from '@codemirror/view'
-import { extractFrontmatter } from '@hedgedoc/commons'
+import { extractFrontmatter, parseRawFrontmatterFromYaml, parseTags } from '@hedgedoc/commons'
 import { t } from 'i18next'
-import { load } from 'js-yaml'
 
 /**
  * Creates a {@link Linter linter} for the yaml frontmatter.
@@ -23,27 +21,42 @@ export class FrontmatterLinter implements Linter {
     if (frontmatterExtraction === undefined) {
       return []
     }
-    const startOfYaml = lines[0].length + 1
     const frontmatterLines = lines.slice(1, frontmatterExtraction.lineOffset - 1)
-    const rawNoteFrontmatter = FrontmatterLinter.loadYaml(frontmatterExtraction.rawText)
-    if (rawNoteFrontmatter === undefined) {
+    const startOfYaml = lines[0].length + 1
+    const endOfYaml = startOfYaml + frontmatterLines.join('\n').length
+    const rawNoteFrontmatter = parseRawFrontmatterFromYaml(frontmatterExtraction.rawText)
+    if (rawNoteFrontmatter.error) {
+      return this.createErrorDiagnostics(startOfYaml, endOfYaml, rawNoteFrontmatter.error, 'error')
+    } else if (rawNoteFrontmatter.warning) {
+      return this.createErrorDiagnostics(startOfYaml, endOfYaml, rawNoteFrontmatter.warning, 'warning')
+    } else if (!Array.isArray(rawNoteFrontmatter.value.tags)) {
+      return this.createReplaceSingleStringTagsDiagnostic(rawNoteFrontmatter.value.tags, frontmatterLines, startOfYaml)
+    }
+    return []
+  }
+
+  private createErrorDiagnostics(
+    startOfYaml: number,
+    endOfYaml: number,
+    error: Error,
+    severity: 'error' | 'warning'
+  ): Diagnostic[] {
     return [
       {
         from: startOfYaml,
-          to: startOfYaml + frontmatterLines.join('\n').length,
-          message: t('editor.linter.frontmatter'),
-          severity: 'error'
+        to: endOfYaml,
+        message: error.message,
+        severity: severity
       }
     ]
   }
-    if (typeof rawNoteFrontmatter.tags !== 'string' && typeof rawNoteFrontmatter.tags !== 'number') {
-      return []
-    }
-    const tags: string[] =
-      rawNoteFrontmatter?.tags
-        .toString()
-        .split(',')
-        .map((entry) => entry.trim()) ?? []
+
+  private createReplaceSingleStringTagsDiagnostic(
+    rawTags: string,
+    frontmatterLines: string[],
+    startOfYaml: number
+  ): Diagnostic[] {
+    const tags: string[] = parseTags(rawTags)
     const replacedText = 'tags:\n- ' + tags.join('\n- ')
     const tagsLineIndex = frontmatterLines.findIndex((value) => value.startsWith('tags: '))
     const linesBeforeTagsLine = frontmatterLines.slice(0, tagsLineIndex)
@@ -68,12 +81,4 @@ export class FrontmatterLinter implements Linter {
       }
     ]
   }
-
-  private static loadYaml(raw: string): RawNoteFrontmatter | undefined {
-    try {
-      return load(raw) as RawNoteFrontmatter
-    } catch {
-      return undefined
-    }
-  }
 }

frontend/src/redux/note-details/build-state-from-updated-markdown-content.ts

@@ -5,10 +5,15 @@
  */
 import { calculateLineStartIndexes } from './calculate-line-start-indexes'
 import { initialState } from './initial-state'
-import { createNoteFrontmatterFromYaml } from './raw-note-frontmatter-parser/parser'
 import type { NoteDetails } from './types/note-details'
-import { extractFrontmatter, generateNoteTitle } from '@hedgedoc/commons'
-import type { FrontmatterExtractionResult } from '@hedgedoc/commons'
+import type { FrontmatterExtractionResult, NoteFrontmatter } from '@hedgedoc/commons'
+import {
+  convertRawFrontmatterToNoteFrontmatter,
+  extractFrontmatter,
+  generateNoteTitle,
+  parseRawFrontmatterFromYaml
+} from '@hedgedoc/commons'
+import { Optional } from '@mrdrogdrog/optional'
 
 /**
  * Copies a {@link NoteDetails} but with another markdown content.
@@ -62,7 +67,7 @@ const buildStateFromMarkdownContentAndLines = (
       },
       startOfContentLineOffset: 0,
       rawFrontmatter: '',
-      title: generateNoteTitle(initialState.frontmatter, state.firstHeading),
+      title: generateNoteTitle(initialState.frontmatter, () => state.firstHeading),
       frontmatter: initialState.frontmatter
     }
   }
@@ -81,22 +86,27 @@ const buildStateFromFrontmatterUpdate = (
   if (frontmatterExtraction.rawText === state.rawFrontmatter) {
     return state
   }
-  try {
-    const frontmatter = createNoteFrontmatterFromYaml(frontmatterExtraction.rawText)
-    return {
-      ...state,
-      rawFrontmatter: frontmatterExtraction.rawText,
-      frontmatter: frontmatter,
-      title: generateNoteTitle(frontmatter, state.firstHeading),
-      startOfContentLineOffset: frontmatterExtraction.lineOffset
+  return buildStateFromFrontmatter(state, parseFrontmatter(frontmatterExtraction), frontmatterExtraction)
 }
-  } catch (e) {
+
+const parseFrontmatter = (frontmatterExtraction: FrontmatterExtractionResult) => {
+  return Optional.of(parseRawFrontmatterFromYaml(frontmatterExtraction.rawText))
+    .filter((frontmatter) => frontmatter.error === undefined)
+    .map((frontmatter) => frontmatter.value)
+    .map((value) => convertRawFrontmatterToNoteFrontmatter(value))
+    .orElse(initialState.frontmatter)
+}
+
+const buildStateFromFrontmatter = (
+  state: NoteDetails,
+  noteFrontmatter: NoteFrontmatter,
+  frontmatterExtraction: FrontmatterExtractionResult
+) => {
   return {
     ...state,
-      title: generateNoteTitle(initialState.frontmatter, state.firstHeading),
+    title: generateNoteTitle(noteFrontmatter, () => state.firstHeading),
     rawFrontmatter: frontmatterExtraction.rawText,
-      frontmatter: initialState.frontmatter,
+    frontmatter: noteFrontmatter,
     startOfContentLineOffset: frontmatterExtraction.lineOffset
   }
 }
-}

frontend/src/redux/note-details/initial-state.ts

@@ -4,16 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 import type { NoteDetails } from './types/note-details'
-import { NoteTextDirection, NoteType } from '@hedgedoc/commons'
-import type { SlideOptions } from '@hedgedoc/commons'
-
-export const initialSlideOptions: SlideOptions = {
-  transition: 'zoom',
-  autoSlide: 0,
-  autoSlideStoppable: true,
-  backgroundTransition: 'fade',
-  slideNumber: false
-}
+import { defaultNoteFrontmatter } from '@hedgedoc/commons'
 
 export const initialState: NoteDetails = {
   updateUsername: null,
@@ -40,17 +31,5 @@ export const initialState: NoteDetails = {
   editedBy: [],
   title: '',
   firstHeading: '',
-  frontmatter: {
-    title: '',
-    description: '',
-    tags: [],
-    robots: '',
-    lang: 'en',
-    dir: NoteTextDirection.LTR,
-    newlinesAreBreaks: true,
-    license: '',
-    type: NoteType.DOCUMENT,
-    opengraph: {},
-    slideOptions: initialSlideOptions
-  }
+  frontmatter: defaultNoteFrontmatter
 }

frontend/src/redux/note-details/raw-note-frontmatter-parser/parser.spec.ts

@@ -1,64 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import { createNoteFrontmatterFromYaml } from './parser'
-
-describe('yaml frontmatter', () => {
-  it('should parse "title"', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml('title: test')
-    expect(noteFrontmatter.title).toEqual('test')
-  })
-
-  it('should parse "robots"', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml('robots: index, follow')
-    expect(noteFrontmatter.robots).toEqual('index, follow')
-  })
-
-  it('should parse the deprecated tags syntax', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml('tags: test123, abc')
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-  })
-
-  it('should parse the tags list syntax', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml(`tags:
-      - test123
-      - abc
-    `)
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-  })
-
-  it('should parse the tag inline-list syntax', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml("tags: ['test123', 'abc']")
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-  })
-
-  it('should parse "breaks"', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml('breaks: false')
-    expect(noteFrontmatter.newlinesAreBreaks).toEqual(false)
-  })
-
-  it('should parse an empty opengraph object', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml('opengraph:')
-    expect(noteFrontmatter.opengraph).toEqual({})
-  })
-
-  it('should parse an opengraph title', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml(`opengraph:
-      title: Testtitle
-    `)
-    expect(noteFrontmatter.opengraph.title).toEqual('Testtitle')
-  })
-
-  it('should parse multiple opengraph values', () => {
-    const noteFrontmatter = createNoteFrontmatterFromYaml(`opengraph:
-      title: Testtitle
-      image: https://dummyimage.com/48.png
-      image:type: image/png
-    `)
-    expect(noteFrontmatter.opengraph.title).toEqual('Testtitle')
-    expect(noteFrontmatter.opengraph.image).toEqual('https://dummyimage.com/48.png')
-    expect(noteFrontmatter.opengraph['image:type']).toEqual('image/png')
-  })
-})

frontend/src/redux/note-details/raw-note-frontmatter-parser/parser.ts

@@ -1,139 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import { initialSlideOptions, initialState } from '../initial-state'
-import type { RawNoteFrontmatter } from './types'
-import type { Iso6391Language, NoteFrontmatter, OpenGraph, SlideOptions } from '@hedgedoc/commons'
-import { ISO6391, NoteTextDirection, NoteType } from '@hedgedoc/commons'
-import { load } from 'js-yaml'
-
-/**
- * Creates a new frontmatter metadata instance based on a raw yaml string.
- * @param rawYaml The frontmatter content in yaml format.
- * @throws Error when the content string is invalid yaml.
- * @return Frontmatter metadata instance containing the parsed properties from the yaml content.
- */
-export const createNoteFrontmatterFromYaml = (rawYaml: string): NoteFrontmatter => {
-  const rawNoteFrontmatter = load(rawYaml) as RawNoteFrontmatter
-  return parseRawNoteFrontmatter(rawNoteFrontmatter)
-}
-
-/**
- * Creates a new frontmatter metadata instance based on the given raw metadata properties.
- * @param rawData A {@link RawNoteFrontmatter} object containing the properties of the parsed yaml frontmatter.
- */
-const parseRawNoteFrontmatter = (rawData: RawNoteFrontmatter): NoteFrontmatter => {
-  let tags: string[]
-  if (typeof rawData?.tags === 'string') {
-    tags = rawData?.tags?.split(',').map((entry) => entry.trim()) ?? []
-  } else if (typeof rawData?.tags === 'object') {
-    tags = rawData?.tags?.filter((tag) => tag !== null) ?? []
-  } else {
-    tags = [...initialState.frontmatter.tags]
-  }
-
-  return {
-    title: rawData.title ?? initialState.frontmatter.title,
-    description: rawData.description ?? initialState.frontmatter.description,
-    robots: rawData.robots ?? initialState.frontmatter.robots,
-    newlinesAreBreaks: parseBoolean(rawData.breaks) ?? initialState.frontmatter.newlinesAreBreaks,
-    lang: parseLanguage(rawData),
-    type: parseNoteType(rawData),
-    dir: parseTextDirection(rawData),
-    opengraph: parseOpenGraph(rawData),
-    slideOptions: parseSlideOptions(rawData),
-    license: rawData.license ?? initialState.frontmatter.license,
-    tags
-  }
-}
-
-/**
- * Parses the {@link OpenGraph open graph} from the {@link RawNoteFrontmatter}.
- *
- * @param rawData The raw note frontmatter data.
- * @return the parsed {@link OpenGraph open graph}
- */
-const parseOpenGraph = (rawData: RawNoteFrontmatter): OpenGraph => {
-  return { ...(rawData.opengraph ?? initialState.frontmatter.opengraph) }
-}
-
-/**
- * Parses the {@link Iso6391Language iso 6391 language code} from the {@link RawNoteFrontmatter}.
- *
- * @param rawData The raw note frontmatter data.
- * @return the parsed {@link Iso6391Language iso 6391 language code}
- */
-const parseLanguage = (rawData: RawNoteFrontmatter): Iso6391Language => {
-  return (rawData.lang ? ISO6391.find((lang) => lang === rawData.lang) : undefined) ?? initialState.frontmatter.lang
-}
-
-/**
- * Parses the {@link NoteType note type} from the {@link RawNoteFrontmatter}.
- *
- * @param rawData The raw note frontmatter data.
- * @return the parsed {@link NoteType note type}
- */
-const parseNoteType = (rawData: RawNoteFrontmatter): NoteType => {
-  return rawData.type !== undefined
-    ? rawData.type === NoteType.SLIDE
-      ? NoteType.SLIDE
-      : NoteType.DOCUMENT
-    : initialState.frontmatter.type
-}
-
-/**
- * Parses the {@link NoteTextDirection note text direction} from the {@link RawNoteFrontmatter}.
- *
- * @param rawData The raw note frontmatter data.
- * @return the parsed {@link NoteTextDirection note text direction}
- */
-const parseTextDirection = (rawData: RawNoteFrontmatter): NoteTextDirection => {
-  return rawData.dir !== undefined
-    ? rawData.dir === NoteTextDirection.LTR
-      ? NoteTextDirection.LTR
-      : NoteTextDirection.RTL
-    : initialState.frontmatter.dir
-}
-
-/**
- * Parses the {@link SlideOptions} from the {@link RawNoteFrontmatter}.
- *
- * @param rawData The raw note frontmatter data.
- * @return the parsed slide options
- */
-const parseSlideOptions = (rawData: RawNoteFrontmatter): SlideOptions => {
-  const rawSlideOptions = rawData?.slideOptions
-  return {
-    autoSlide: parseNumber(rawSlideOptions?.autoSlide) ?? initialSlideOptions.autoSlide,
-    transition: rawSlideOptions?.transition ?? initialSlideOptions.transition,
-    backgroundTransition: rawSlideOptions?.backgroundTransition ?? initialSlideOptions.backgroundTransition,
-    autoSlideStoppable: parseBoolean(rawSlideOptions?.autoSlideStoppable) ?? initialSlideOptions.autoSlideStoppable,
-    slideNumber: parseBoolean(rawSlideOptions?.slideNumber) ?? initialSlideOptions.slideNumber
-  }
-}
-
-/**
- * Parses an unknown variable into a boolean.
- *
- * @param rawData The raw data
- * @return The parsed boolean or undefined if it's not possible to parse the data.
- */
-const parseBoolean = (rawData: unknown | undefined): boolean | undefined => {
-  return rawData === undefined ? undefined : rawData === true
-}
-
-/**
- * Parses an unknown variable into a number.
- *
- * @param rawData The raw data
- * @return The parsed number or undefined if it's not possible to parse the data.
- */
-const parseNumber = (rawData: unknown | undefined): number | undefined => {
-  if (rawData === undefined) {
-    return undefined
-  }
-  const numValue = Number(rawData)
-  return isNaN(numValue) ? undefined : numValue
-}

frontend/src/redux/note-details/raw-note-frontmatter-parser/types.d.ts

@@ -1,19 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-export interface RawNoteFrontmatter {
-  title: string | undefined
-  description: string | undefined
-  tags: string | number | string[] | undefined
-  robots: string | undefined
-  lang: string | undefined
-  dir: string | undefined
-  breaks: boolean | undefined
-  license: string | undefined
-  type: string | undefined
-  slideOptions: { [key: string]: string } | null
-  opengraph: { [key: string]: string } | null
-}

frontend/src/redux/note-details/reducers/build-state-from-first-heading-update.ts

@@ -16,6 +16,6 @@ export const buildStateFromFirstHeadingUpdate = (state: NoteDetails, firstHeadin
   return {
     ...state,
     firstHeading: firstHeading,
-    title: generateNoteTitle(state.frontmatter, firstHeading)
+    title: generateNoteTitle(state.frontmatter, () => firstHeading)
   }
 }

yarn.lock

@@ -2386,6 +2386,7 @@ __metadata:
     eventemitter2: 6.4.9
     isomorphic-ws: 5.0.0
     jest: 29.5.0
+    joi: 17.9.2
     microbundle: 0.15.1
     prettier: 2.8.8
     reveal.js: 4.5.0