10c - adfToPlainMarkdown and plainMarkdownToAdf exported, whitespace-only leaves trimmed at a line end

src/conformance/adf-property.test.ts

@@ -4,10 +4,21 @@ import test from 'node:test'
 
 import { adfDocument, propertyRuns, propertyTimeout } from './property-harness.ts'
 import { adfToMarkdown } from '../markdown/emit/adf-to-markdown.ts'
+import { adfToPlainMarkdown } from '../markdown/emit/plain-reduction.ts'
+import { directivePrefix } from '../markdown/directive-syntax.ts'
 import { markdownToAdf } from '../markdown/parse/markdown-to-adf.ts'
+import { plainMarkdownToAdf } from '../markdown/parse/plain-lift.ts'
 import { toEditorNormal } from '../adf/editor-normal.ts'
 
 const gateRuns = 1600
+const renamedPrefix = '!adg:'
+
+// Renaming the prefix changes what markdown reads only where a directive was read.
+function readsNoDirective(markdown: string): boolean {
+  const read = markdownToAdf(markdown)
+  const renamed = markdownToAdf(markdown.replaceAll(directivePrefix, renamedPrefix))
+  return read.ok && renamed.ok && JSON.stringify(read.value).replaceAll(directivePrefix, renamedPrefix) === JSON.stringify(renamed.value)
+}
 
 test('a generated document refuses to emit, or its markdown reads back to it', { timeout: propertyTimeout }, () => {
   fc.assert(
@@ -21,3 +32,17 @@ test('a generated document refuses to emit, or its markdown reads back to it', {
     propertyRuns(gateRuns),
   )
 })
+
+test('a generated document writes plain markdown refusing only what the guard refuses, and that markdown reads back to itself', { timeout: propertyTimeout }, () => {
+  fc.assert(
+    fc.property(adfDocument, (document) => {
+      const written = adfToPlainMarkdown(document)
+      assert.ok(written.ok, written.ok ? '' : `${written.error.code}: ${written.error.message}`)
+      assert.ok(readsNoDirective(written.value), `a directive in ${JSON.stringify(written.value)}`)
+      const read = plainMarkdownToAdf(written.value)
+      assert.ok(read.ok, read.ok ? '' : `${read.error.code}: ${read.error.message} — reading ${JSON.stringify(written.value)}`)
+      assert.deepEqual(adfToPlainMarkdown(read.value), written, `reading ${JSON.stringify(written.value)}`)
+    }),
+    propertyRuns(gateRuns),
+  )
+})

src/index.ts

@@ -2,5 +2,7 @@ export type { AdfAttributes, AdfDocument, AdfMark, AdfNode } from './adf/documen
 export type { ConvertError, ConvertErrorCode, ConvertErrorPath, ParseError, Result, SourcePosition } from './result.ts'
 export type { JsonValue } from './json-value.ts'
 export { adfToMarkdown } from './markdown/emit/adf-to-markdown.ts'
+export { adfToPlainMarkdown } from './markdown/emit/plain-reduction.ts'
 export { isAdfDocument } from './adf/document.ts'
 export { markdownToAdf } from './markdown/parse/markdown-to-adf.ts'
+export { plainMarkdownToAdf } from './markdown/parse/plain-lift.ts'

src/markdown/emit/plain-inline.ts

@@ -221,10 +221,11 @@ function leafEdges(leaf: AdfNode, previous: AdfNode | undefined, next: AdfNode |
   const text = leaf.text
   if (text === undefined || marks.some((mark) => mark.type === 'code')) return undefined
   const lead = text.slice(0, text.search(/[^ \t]|$/))
-  const trail = lead === text ? '' : text.slice(text.search(/[ \t]*$/))
+  const trail = text.slice(Math.max(lead.length, text.search(/[ \t]*$/)))
   const leadDepth = edgeDepth(marks, previous, lead)
-  const trailDepth = edgeDepth(marks, next, trail)
+  const trailDepth = edgeDepth(marks, next, lead === text ? text : trail)
   if (leadDepth === marks.length && trailDepth === marks.length) return undefined
+  if (lead === text) return leadDepth === undefined || trailDepth === undefined ? [] : [textLeaf(text, marks.slice(0, Math.min(leadDepth, trailDepth)))]
   const edges: AdfNode[] = []
   if (lead !== '' && leadDepth !== undefined) edges.push(textLeaf(lead, marks.slice(0, leadDepth)))
   const core = text.slice(lead.length, text.length - trail.length)

src/markdown/emit/plain-reduction.test.ts

@@ -229,6 +229,7 @@ test('spells a node no row names, or one standing where no spelling holds it, as
   assert.equal(plain(bulletList(said('stray'), item(said('b')), text('loose'))), '- stray\n- b\n- loose\n')
   assert.equal(plain(bulletList()), '')
   assert.equal(plain(bulletList(item({ content: [text('a\n  \nb')], type: 'codeBlock' }))), '- ```\n  a\n\n  b\n  ```\n')
+  assert.equal(plain(bulletList(item({ content: [text(' ')], type: 'codeBlock' }))), '- ```\n  ```\n')
   assert.equal(plain(bulletList(item(node('rule', {}), node('rule', {}), said('Install')), item(said('Configure')))), '- Install\n- Configure\n')
   assert.equal(plain(bulletList(item(node('rule', {}), node('rule', {})), item(said('Configure')))), '-\n- Configure\n')
   assert.equal(plain(bulletList(item(bulletList(item(bulletList(item())))))), '- -\n')
@@ -285,6 +286,7 @@ test('breaks a line at a newline and trims whitespace at every edge CommonMark s
   assert.equal(plain(paragraph(text(' \n a \n b\n'))), 'a\\\nb\n')
   assert.equal(plain(paragraph({ type: 'hardBreak' }, text('a'), { attrs: { text: '\n' }, type: 'hardBreak' }, text('b'), { type: 'hardBreak' })), 'a\\\nb\n')
   assert.equal(plain(paragraph(text('a'), text(' b ', strong), text('c'))), 'a **b** c\n')
+  assert.equal(plain(paragraph(text(' '), text('b', strong), text(' \n'), text('c', strong), text(' '))), '**b**\\\n**c**\n')
   assert.equal(plain(paragraph(text('a'), text(' b ', em, strong), text(' ', em), text('c', em))), 'a _**b**  c_\n')
   assert.equal(plain(paragraph(text(' x ', code))), '`  x  `\n')
   assert.equal(plain(node('heading', { level: 1 }, text(' h\ni '))), '# h i\n')

src/markdown/emit/plain-reduction.ts

@@ -2,7 +2,7 @@ import type { AdfDocument, AdfNode } from '../../adf/document.ts'
 import { adfDocumentFault, nodeAttrs, nodeContent } from '../../adf/document.ts'
 import { alertMarker, foldedAlertMarker, taskMarker } from '../plain-conventions.ts'
 import { blockNodeModel } from '../../adf/block-nodes.ts'
-import { commonMarkSpelling, largestListMarker, type SpellingMemo } from './adf-to-markdown.ts'
+import { adfToMarkdown, commonMarkSpelling, largestListMarker, type SpellingMemo } from './adf-to-markdown.ts'
 import { failure, faulted, success, type ConvertErrorPath, type Result } from '../../result.ts'
 import { inlineLeaves, isBlockNodeType, oneLine, reduceInline, writableHref } from './plain-inline.ts'
 import { inlineNodeModel } from '../../adf/inline-nodes.ts'
@@ -41,6 +41,11 @@ const blockReducers: Readonly<Record<string, BlockReducer>> = {
   taskList: reduceTaskList,
 }
 
+export function adfToPlainMarkdown(document: AdfDocument): Result<string> {
+  const reduced = reduceToPlain(document)
+  return reduced.ok ? adfToMarkdown(reduced.value) : reduced
+}
+
 export function reduceToPlain(document: AdfDocument): Result<AdfDocument> {
   const fault = adfDocumentFault(document)
   if (fault !== undefined) return faulted(fault, [])
@@ -224,12 +229,13 @@ function listItem(blocks: Result<AdfNode[]>): Result<AdfNode[]> {
 // A list item's first line reads as no rule and holds no line of spaces alone: the rule and the spaces give way.
 function itemOf(blocks: readonly AdfNode[]): AdfNode {
   const rules = blocks.findIndex((block) => block.type !== 'rule')
-  const content = blocks.slice(rules === -1 ? blocks.length : rules).map((block) => (block.type === 'codeBlock' ? { ...block, content: nodeContent(block).map(blankedLines) } : block))
+  const content = blocks.slice(rules === -1 ? blocks.length : rules).map((block) => (block.type === 'codeBlock' ? { ...block, content: blankedLines(nodeContent(block)) } : block))
   return { content, type: 'listItem' }
 }
 
-function blankedLines(code: AdfNode): AdfNode {
-  return code.text === undefined ? code : { ...code, text: code.text.replace(/^[ \t]+$/gm, '') }
+function blankedLines(code: readonly AdfNode[]): AdfNode[] {
+  const blanked = code.map((leaf) => leaf.text ?? '').join('').replace(/^[ \t]+$/gm, '')
+  return blanked === '' ? [] : [text(blanked)]
 }
 
 function reduceTaskList(node: AdfNode, reduction: Reduction): Result<AdfNode[]> {

src/markdown/parse/plain-lift.ts

@@ -2,8 +2,10 @@ import type { AdfDocument, AdfMark, AdfNode } from '../../adf/document.ts'
 import { blockNodeModel } from '../../adf/block-nodes.ts'
 import { isWordCharacter } from '../commonmark/emphasis-matching.ts'
 import { highlightDelimiter, readAlertMarker, readTaskMarker } from '../plain-conventions.ts'
+import { markdownToAdf } from './markdown-to-adf.ts'
 import { mergeAdjacentText, sameMarks } from '../../adf/editor-normal.ts'
 import { nodeAttrs, nodeContent, nodeMarks } from '../../adf/document.ts'
+import { success, type ParseError, type Result } from '../../result.ts'
 
 type Delimiter = { closes: boolean; holder: AdfNode; line: number; node: number; offset: number; opens: boolean; position: number }
 
@@ -11,6 +13,11 @@ type MarkerLed<T> = { marker: T; rest: AdfNode[] }
 
 const editorHighlight: AdfMark = { attrs: { color: '#f8e6a0' }, type: 'backgroundColor' }
 
+export function plainMarkdownToAdf(markdown: string): Result<AdfDocument, ParseError> {
+  const parsed = markdownToAdf(markdown)
+  return parsed.ok ? success(liftFromPlain(parsed.value)) : parsed
+}
+
 export function liftFromPlain(document: AdfDocument): AdfDocument {
   return { ...document, content: liftBlocks(nodeContent(document), false) }
 }