Add reusable prettier wrapper CLI (denoland/deno_std#165)

This also fixes an issue with the path on azure-pipelines.

Original: https://github.com/denoland/deno_std/commit/e7837ff0f007d8f2175ec58ae3065dabfb4823f1

1 files changed, 248 insertions, 0 deletions

diff --git a/prettier/main.ts b/prettier/main.ts
new file mode 100755
index 000000000..435206dcd
--- /dev/null
+++ b/prettier/main.ts
@@ -0,0 +1,248 @@
+#!/usr/bin/env deno --allow-run --allow-write
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+// This script formats the given source files. If the files are omitted, it
+// formats the all files in the repository.
+import {
+  args,
+  platform,
+  readAll,
+  lstat,
+  exit,
+  run,
+  readFile,
+  writeFile
+} from "deno";
+import { xrun } from "./util.ts";
+import { parse } from "../flags/mod.ts";
+import { prettier, prettierPlugins } from "./prettier.ts";
+
+const HELP_MESSAGE = `
+Formats the given files. If no arg is passed, then formats the all files.
+
+Usage: deno prettier/main.ts [options] [files...]
+
+Options:
+  -H, --help                 Show this help message and exit.
+  --check                    Check if the source files are formatted.
+  --ignore <path>            Ignore the given path(s).
+
+Example:
+  deno prettier/main.ts script1.ts script2.js
+                             Formats the files
+
+  deno prettier/main.ts --check script1.ts script2.js
+                             Checks if the files are formatted
+
+  deno prettier/main.ts
+                             Formats the all files in the repository
+`;
+
+// Available parsers
+type ParserLabel = "typescript" | "babel" | "markdown" | "json";
+
+const encoder = new TextEncoder();
+const decoder = new TextDecoder();
+
+// Lists files in the given directory.
+// TODO: Replace git usage with deno's API calls
+async function listFiles(dir: string = "."): Promise<string[]> {
+  return decoder
+    .decode(
+      await readAll(
+        xrun({
+          args: ["git", "ls-files", dir],
+          stdout: "piped"
+        }).stdout
+      )
+    )
+    .trim()
+    .split(/\r?\n/);
+}
+
+async function getSourceFiles(args: string[]): Promise<string[]> {
+  if (args.length === 0) {
+    return listFiles();
+  }
+
+  const results = args.map(async path => {
+    if ((await lstat(path)).isDirectory()) {
+      return listFiles(path);
+    }
+
+    return path;
+  });
+
+  return [].concat(...(await Promise.all(results)));
+}
+
+// Filters out the files which contains any pattern in the given ignoreList.
+function filterIgnoreList(files: string[], ignoreList: string[]) {
+  return files.filter(path =>
+    ignoreList.every(pattern => !path.includes(pattern))
+  );
+}
+
+async function readFileIfExists(filename: string): Promise<string | null> {
+  let data;
+  try {
+    data = await readFile(filename);
+  } catch (e) {
+    // The file is deleted. Returns null.
+    return null;
+  }
+
+  return decoder.decode(data);
+}
+
+/**
+ * Checks if the file has been formatted with prettier.
+ */
+async function checkFile(
+  filename: string,
+  parser: ParserLabel
+): Promise<boolean> {
+  const text = await readFileIfExists(filename);
+
+  if (!text) {
+    // The file is deleted. Skip.
+    return;
+  }
+
+  const formatted = prettier.check(text, {
+    parser,
+    plugins: prettierPlugins
+  });
+
+  if (!formatted) {
+    // TODO: print some diff info here to show why this failed
+    console.error(`${filename} ... Not formatted`);
+  }
+
+  return formatted;
+}
+
+/**
+ * Formats the given file.
+ */
+async function formatFile(
+  filename: string,
+  parser: ParserLabel
+): Promise<void> {
+  const text = await readFileIfExists(filename);
+
+  if (!text) {
+    // The file is deleted. Skip.
+    return;
+  }
+
+  const formatted = prettier.format(text, {
+    parser,
+    plugins: prettierPlugins
+  });
+
+  if (text !== formatted) {
+    console.log(`Formatting ${filename}`);
+    await writeFile(filename, encoder.encode(formatted));
+  }
+}
+
+/**
+ * Selects the right prettier parser for the given path.
+ */
+function selectParser(path: string): ParserLabel | null {
+  if (/\.ts$/.test(path)) {
+    return "typescript";
+  } else if (/\.js$/.test(path)) {
+    return "babel";
+  } else if (/\.json$/.test(path)) {
+    return "json";
+  } else if (/\.md$/.test(path)) {
+    return "markdown";
+  }
+
+  return null;
+}
+
+/**
+ * Checks if the files of the given paths have been formatted with prettier.
+ * If paths are empty, then checks all the files.
+ */
+async function checkSourceFiles(
+  args: string[],
+  ignoreList: string[]
+): Promise<void> {
+  const checks = [];
+
+  filterIgnoreList(await getSourceFiles(args), ignoreList).forEach(file => {
+    const parser = selectParser(file);
+    if (parser) {
+      checks.push(checkFile(file, parser));
+    }
+  });
+
+  const results = await Promise.all(checks);
+
+  if (results.every(result => result)) {
+    console.log("Every file is formatted");
+    exit(0);
+  } else {
+    console.log("Some files are not formatted");
+    exit(1);
+  }
+}
+
+/**
+ * Formats the files of the given paths with prettier.
+ * If paths are empty, then formats all the files.
+ */
+async function formatSourceFiles(
+  args: string[],
+  ignoreList: string[]
+): Promise<void> {
+  const formats = [];
+
+  filterIgnoreList(await getSourceFiles(args), ignoreList).forEach(file => {
+    const parser = selectParser(file);
+    if (parser) {
+      formats.push(formatFile(file, parser));
+    }
+  });
+
+  await Promise.all(formats);
+  exit(0);
+}
+
+async function main(opts) {
+  const { help, ignore, check, _: args } = opts;
+
+  if (help) {
+    console.log(HELP_MESSAGE);
+    exit(0);
+  }
+
+  const ignoreList: string[] = Array.isArray(ignore) ? ignore : [ignore];
+
+  try {
+    if (check) {
+      await checkSourceFiles(args, ignoreList);
+    } else {
+      await formatSourceFiles(args, ignoreList);
+    }
+  } catch (e) {
+    console.log(e);
+    exit(1);
+  }
+}
+
+main(
+  parse(args.slice(1), {
+    string: ["ignore"],
+    boolean: ["check", "help"],
+    default: {
+      ignore: []
+    },
+    alias: {
+      H: "help"
+    }
+  })
+);