Add mobile Tasks parity (#2452)

Co-authored-by: Orca <help@stably.ai>
2026-10-08 08:02:32 +00:00 · 2026-05-21 20:26:07 -07:00
parent 3efc669bd4
commit b1973657ea
123 changed files with 26492 additions and 1461 deletions
@@ -0,0 +1,168 @@
+export type GitHubPrFileDiffLine = {
+  key: string
+  kind: 'context' | 'added' | 'removed'
+  oldLineNumber?: number
+  newLineNumber?: number
+  text: string
+}
+
+type DiffOperation =
+  | { kind: 'context'; oldLine: string; newLine: string }
+  | { kind: 'removed'; oldLine: string }
+  | { kind: 'added'; newLine: string }
+
+const EXACT_DIFF_CELL_LIMIT = 160_000
+
+function splitContentLines(value: string): string[] {
+  if (!value) {
+    return []
+  }
+  const lines = value.split(/\r?\n/)
+  return lines.at(-1) === '' ? lines.slice(0, -1) : lines
+}
+
+function exactLineDiff(original: string[], modified: string[]): DiffOperation[] {
+  const rowWidth = modified.length + 1
+  const table = new Uint16Array((original.length + 1) * rowWidth)
+
+  for (let oldIndex = original.length - 1; oldIndex >= 0; oldIndex -= 1) {
+    for (let newIndex = modified.length - 1; newIndex >= 0; newIndex -= 1) {
+      const cell = oldIndex * rowWidth + newIndex
+      if (original[oldIndex] === modified[newIndex]) {
+        table[cell] = table[(oldIndex + 1) * rowWidth + newIndex + 1] + 1
+      } else {
+        table[cell] = Math.max(
+          table[(oldIndex + 1) * rowWidth + newIndex],
+          table[oldIndex * rowWidth + newIndex + 1]
+        )
+      }
+    }
+  }
+
+  const operations: DiffOperation[] = []
+  let oldIndex = 0
+  let newIndex = 0
+  while (oldIndex < original.length && newIndex < modified.length) {
+    const oldLine = original[oldIndex]
+    const newLine = modified[newIndex]
+    if (oldLine === newLine) {
+      operations.push({ kind: 'context', oldLine, newLine })
+      oldIndex += 1
+      newIndex += 1
+      continue
+    }
+    const removeScore = table[(oldIndex + 1) * rowWidth + newIndex]
+    const addScore = table[oldIndex * rowWidth + newIndex + 1]
+    if (removeScore >= addScore) {
+      operations.push({ kind: 'removed', oldLine })
+      oldIndex += 1
+    } else {
+      operations.push({ kind: 'added', newLine })
+      newIndex += 1
+    }
+  }
+  while (oldIndex < original.length) {
+    operations.push({ kind: 'removed', oldLine: original[oldIndex] })
+    oldIndex += 1
+  }
+  while (newIndex < modified.length) {
+    operations.push({ kind: 'added', newLine: modified[newIndex] })
+    newIndex += 1
+  }
+  return operations
+}
+
+function buildMiddleDiff(original: string[], modified: string[]): DiffOperation[] {
+  if (original.length === 0) {
+    return modified.map((newLine) => ({ kind: 'added', newLine }))
+  }
+  if (modified.length === 0) {
+    return original.map((oldLine) => ({ kind: 'removed', oldLine }))
+  }
+  if (original.length * modified.length <= EXACT_DIFF_CELL_LIMIT) {
+    return exactLineDiff(original, modified)
+  }
+  // Why: very large files must still show all content without an O(n*m) mobile stall.
+  return [
+    ...original.map((oldLine) => ({ kind: 'removed' as const, oldLine })),
+    ...modified.map((newLine) => ({ kind: 'added' as const, newLine }))
+  ]
+}
+
+export function buildGitHubPrFileDiffLines(
+  originalContent: string,
+  modifiedContent: string
+): GitHubPrFileDiffLine[] {
+  const originalLines = splitContentLines(originalContent)
+  const modifiedLines = splitContentLines(modifiedContent)
+  let prefixLength = 0
+  while (
+    prefixLength < originalLines.length &&
+    prefixLength < modifiedLines.length &&
+    originalLines[prefixLength] === modifiedLines[prefixLength]
+  ) {
+    prefixLength += 1
+  }
+
+  let suffixLength = 0
+  while (
+    suffixLength < originalLines.length - prefixLength &&
+    suffixLength < modifiedLines.length - prefixLength &&
+    originalLines[originalLines.length - suffixLength - 1] ===
+      modifiedLines[modifiedLines.length - suffixLength - 1]
+  ) {
+    suffixLength += 1
+  }
+
+  const prefix = originalLines.slice(0, prefixLength)
+  const originalMiddle = originalLines.slice(
+    prefixLength,
+    suffixLength === 0 ? originalLines.length : originalLines.length - suffixLength
+  )
+  const modifiedMiddle = modifiedLines.slice(
+    prefixLength,
+    suffixLength === 0 ? modifiedLines.length : modifiedLines.length - suffixLength
+  )
+  const suffix = originalLines.slice(originalLines.length - suffixLength)
+  const operations: DiffOperation[] = [
+    ...prefix.map((line) => ({ kind: 'context' as const, oldLine: line, newLine: line })),
+    ...buildMiddleDiff(originalMiddle, modifiedMiddle),
+    ...suffix.map((line) => ({ kind: 'context' as const, oldLine: line, newLine: line }))
+  ]
+
+  const result: GitHubPrFileDiffLine[] = []
+  let oldLineNumber = 1
+  let newLineNumber = 1
+  operations.forEach((operation, index) => {
+    if (operation.kind === 'context') {
+      result.push({
+        key: `${index}:context:${oldLineNumber}:${newLineNumber}`,
+        kind: 'context',
+        oldLineNumber,
+        newLineNumber,
+        text: operation.newLine
+      })
+      oldLineNumber += 1
+      newLineNumber += 1
+      return
+    }
+    if (operation.kind === 'removed') {
+      result.push({
+        key: `${index}:removed:${oldLineNumber}`,
+        kind: 'removed',
+        oldLineNumber,
+        text: operation.oldLine
+      })
+      oldLineNumber += 1
+      return
+    }
+    result.push({
+      key: `${index}:added:${newLineNumber}`,
+      kind: 'added',
+      newLineNumber,
+      text: operation.newLine
+    })
+    newLineNumber += 1
+  })
+  return result
+}