docs: added edit date (#8623)

www/packages/build-scripts/src/generate-edited-dates.ts

@@ -0,0 +1,156 @@
+import { exec } from "child_process"
+import { existsSync } from "fs"
+import { readdir, readFile, stat, writeFile } from "fs/promises"
+import path from "path"
+import util from "util"
+
+const promiseExec = util.promisify(exec)
+
+const projectBasePath = path.resolve()
+const rootPath = path.resolve("..", "..", "..")
+const monorepoRelativePath = projectBasePath
+  .replace(rootPath, "")
+  .replace(/^\//, "")
+const generatedFilePath = path.join(
+  projectBasePath,
+  "generated",
+  "edit-dates.mjs"
+)
+
+const getGitEditDatesOfPaths = async (
+  paths: string[]
+): Promise<Record<string, string>> => {
+  const editDates: Record<string, string> = {}
+  await Promise.all(
+    paths.map(async (filePath) => {
+      const editDateProcess = await promiseExec(
+        `git log -1 --pretty="format:%cI" ${filePath}`
+      )
+
+      editDates[filePath] = editDateProcess.stdout || new Date().toISOString()
+    })
+  )
+
+  return editDates
+}
+
+// Note: this gets the date a file was edited in the OS. One drawback here
+// is if a file is edited on a day, but the PR is merged a few days later, so the
+// date doesn't accurately represent the publish date of the file.
+const getOsLastEditDates = async (
+  paths: string[]
+): Promise<Record<string, string>> => {
+  const editDates: Record<string, string> = {}
+  await Promise.all(
+    paths.map(async (filePath) => {
+      const fileStat = await stat(filePath)
+
+      editDates[filePath] = fileStat.mtime.toISOString()
+    })
+  )
+
+  return editDates
+}
+
+const getChangedFiles = async (): Promise<string[]> => {
+  const changedFiles: string[] = []
+
+  // get untracked files
+  const untrackedFiles = await promiseExec(
+    `git ls-files --other --exclude-standard`
+  )
+
+  untrackedFiles.stdout.split("\n").forEach((file) => {
+    if (path.basename(file) !== "page.mdx") {
+      return
+    }
+
+    changedFiles.push(path.relative(projectBasePath, file))
+  })
+
+  // get tracked files
+  const trackedFiles = await promiseExec(
+    `{ git diff --name-only ; git diff --name-only --staged ; } | sort | uniq`
+  )
+
+  trackedFiles.stdout.split("\n").forEach((file) => {
+    // The above command retrieve the full file path relative to the monorepo
+    // so all parts before the project's path should be removed.
+    if (
+      !file.startsWith(monorepoRelativePath) ||
+      path.basename(file) !== "page.mdx"
+    ) {
+      return
+    }
+
+    changedFiles.push(file.replace(`${monorepoRelativePath}/`, ""))
+  })
+
+  return changedFiles
+}
+
+const getAllProjectFiles = async (): Promise<string[]> => {
+  const appDir = path.join(projectBasePath, "app")
+
+  const allFiles: string[] = []
+  const filesInDir = await readdir(appDir, {
+    withFileTypes: true,
+    recursive: true,
+  })
+
+  filesInDir.forEach((file) => {
+    if (file.isDirectory() || path.basename(file.name) !== "page.mdx") {
+      return
+    }
+
+    const fullFilePath = path.join(file.path, file.name)
+
+    // TODO check if this produces correct file paths
+    allFiles.push(path.relative(projectBasePath, fullFilePath))
+  })
+
+  return allFiles
+}
+
+export const generateEditedDates = async () => {
+  const generatedFileExists = existsSync(generatedFilePath)
+  const type = generatedFileExists ? "git" : "all"
+
+  let files: string[] = []
+  let editDates: Record<string, string> = {}
+
+  if (type === "all") {
+    // get all files in a project
+    files = await getAllProjectFiles()
+    editDates = await getGitEditDatesOfPaths(files)
+  } else {
+    // set the last edit dates for git changes only
+    files = await getChangedFiles()
+    editDates = await getOsLastEditDates(files)
+  }
+
+  if (!files.length) {
+    return
+  }
+
+  const fileContentPrefix = `export const generatedEditDates = `
+
+  if (generatedFileExists) {
+    const existingEditDates = JSON.parse(
+      (await readFile(generatedFilePath, "utf-8")).replace(
+        fileContentPrefix,
+        ""
+      )
+    )
+
+    editDates = Object.assign(existingEditDates, editDates)
+  }
+
+  await writeFile(
+    generatedFilePath,
+    `${fileContentPrefix}${JSON.stringify(editDates, undefined, 2)}`,
+    {
+      flag: "w",
+    }
+  )
+}