Call JS API of jscodeshift instead of using spawn (#349)

Author: trivikr

.changeset/sharp-months-battle.md

@@ -0,0 +1,5 @@
+---
+"aws-sdk-js-codemod": patch
+---
+
+Call JS API of jscodeshift instead of using spawn

src/cli.spec.ts

@@ -18,39 +18,64 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-import { spawn } from "child_process";
+// Most of the code from here is from bin/jscodeshift.js
+// It's kept that way so that users can reuse jscodeshift options.
 
 // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-// @ts-ignore: package.json will be imported from dist folders
-import { version } from "../package.json"; // eslint-disable-line
+// @ts-nocheck
+import Runner from "jscodeshift/dist/Runner";
+import path from "path";
+
 import {
-  getArgsWithUpdatedTransformFile,
   getHelpParagraph,
-  getTransformFileFromArgs,
+  getJsCodeshiftParser,
   getTransforms,
   getUpdatedTransformFile,
 } from "./utils";
 
-export const run = async (args: string[]): Promise<void> => {
-  const transforms = getTransforms();
-
-  if (args[0] === "--version") {
-    process.stdout.write(`aws-sdk-js-codemod: ${version}\n\n`);
-  } else if (args[0] === "--help" || args[0] === "-h") {
-    process.stdout.write(getHelpParagraph(transforms));
-  } else if (args.includes("-t") || args.some((arg) => arg.startsWith("--transform="))) {
-    const transformFile = getTransformFileFromArgs(args);
-    if (transforms.map(({ name }) => name).includes(transformFile)) {
-      const updatedTransformFile = getUpdatedTransformFile(transformFile);
-      args = getArgsWithUpdatedTransformFile(args, updatedTransformFile);
-    }
+const args = process.argv;
+const transforms = getTransforms();
+
+if (args[2] === "--help" || args[2] === "-h") {
+  process.stdout.write(getHelpParagraph(transforms));
+}
+
+const parser = getJsCodeshiftParser();
+
+let options, positionalArguments;
+try {
+  ({ options, positionalArguments } = parser.parse());
+  if (positionalArguments.length === 0 && !options.stdin) {
+    process.stderr.write(
+      "Error: You have to provide at least one file/directory to transform." +
+        "\n\n---\n\n" +
+        parser.getHelpText()
+    );
+    process.exit(1);
   }
-  spawn("npm", ["exec", "jscodeshift", "--", ...args], {
-    stdio: "inherit",
-    shell: process.platform == "win32",
-  });
-};
+} catch (e) {
+  const exitCode = e.exitCode === undefined ? 1 : e.exitCode;
+  (exitCode ? process.stderr : process.stdout).write(e.message);
+  process.exit(exitCode);
+}
+
+const { transform } = options;
+if (transforms.map(({ name }) => name).includes(transform)) {
+  options.transform = getUpdatedTransformFile(transform);
+}
 
-const [, , ...args] = process.argv;
+function run(paths, options) {
+  Runner.run(
+    /^https?/.test(options.transform) ? options.transform : path.resolve(options.transform),
+    paths,
+    options
+  );
+}
 
-run(args);
+if (options.stdin) {
+  let buffer = "";
+  process.stdin.on("data", (data) => (buffer += data));
+  process.stdin.on("end", () => run(buffer.split("\n"), options));
+} else {
+  run(positionalArguments, options);
+}

src/cli.ts

@@ -0,0 +1,154 @@
+// Most of the code from here is from bin/jscodeshift.js
+// It's kept that way so that users can reuse jscodeshift options.
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-nocheck
+
+import { readFileSync } from "fs";
+import argsParser from "jscodeshift/dist/argsParser";
+import { dirname, join } from "path";
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: package.json will be imported from dist folders
+import { version } from "../../package.json";
+
+const requirePackage = (name: string) => {
+  const entry = require.resolve(name);
+  let dir = dirname(entry);
+  while (dir !== "/") {
+    try {
+      // eslint-disable-next-line @typescript-eslint/no-var-requires
+      const pkg = require(join(dir, "package.json"));
+      return pkg.name === name ? pkg : {};
+    } catch (error) {} // eslint-disable-line no-empty
+    dir = dirname(dir);
+  }
+  return {};
+};
+
+/* eslint-disable @typescript-eslint/naming-convention */
+export const getJsCodeshiftParser = () =>
+  argsParser.options({
+    transform: {
+      display_index: 15,
+      abbr: "t",
+      default: "./transform.js",
+      help: "path to the transform file. Can be either a local path or url",
+      metavar: "FILE",
+      required: true,
+    },
+    cpus: {
+      display_index: 1,
+      abbr: "c",
+      help: "start at most N child processes to process source files",
+      defaultHelp: "max(all - 1, 1)",
+      metavar: "N",
+      process: Number,
+    },
+    verbose: {
+      display_index: 16,
+      abbr: "v",
+      choices: [0, 1, 2],
+      default: 0,
+      help: "show more information about the transform process",
+      metavar: "N",
+      process: Number,
+    },
+    dry: {
+      display_index: 2,
+      abbr: "d",
+      flag: true,
+      default: false,
+      help: "dry run (no changes are made to files)",
+    },
+    print: {
+      display_index: 11,
+      abbr: "p",
+      flag: true,
+      default: false,
+      help: "print transformed files to stdout, useful for development",
+    },
+    babel: {
+      display_index: 0,
+      flag: true,
+      default: true,
+      help: "apply babeljs to the transform file",
+    },
+    extensions: {
+      display_index: 3,
+      default: "js",
+      help: "transform files with these file extensions (comma separated list)",
+      metavar: "EXT",
+    },
+    ignorePattern: {
+      display_index: 7,
+      full: "ignore-pattern",
+      list: true,
+      help: "ignore files that match a provided glob expression",
+      metavar: "GLOB",
+    },
+    ignoreConfig: {
+      display_index: 6,
+      full: "ignore-config",
+      list: true,
+      help: "ignore files if they match patterns sourced from a configuration file (e.g. a .gitignore)",
+      metavar: "FILE",
+    },
+    gitignore: {
+      display_index: 8,
+      flag: true,
+      default: false,
+      help: "adds entries the current directory's .gitignore file",
+    },
+    runInBand: {
+      display_index: 12,
+      flag: true,
+      default: false,
+      full: "run-in-band",
+      help: "run serially in the current process",
+    },
+    silent: {
+      display_index: 13,
+      abbr: "s",
+      flag: true,
+      default: false,
+      help: "do not write to stdout or stderr",
+    },
+    parser: {
+      display_index: 9,
+      choices: ["babel", "babylon", "flow", "ts", "tsx"],
+      default: "babel",
+      help: "the parser to use for parsing the source files",
+    },
+    parserConfig: {
+      display_index: 10,
+      full: "parser-config",
+      help: "path to a JSON file containing a custom parser configuration for flow or babylon",
+      metavar: "FILE",
+      process: (file: string) => JSON.parse(readFileSync(file).toString()),
+    },
+    failOnError: {
+      display_index: 4,
+      flag: true,
+      help: "Return a non-zero code when there are errors",
+      full: "fail-on-error",
+      default: false,
+    },
+    version: {
+      display_index: 17,
+      help: "print version and exit",
+      callback: function () {
+        return [
+          `aws-sdk-js-codemod: ${version}`,
+          `- jscodeshift: ${requirePackage("jscodeshift").version}`,
+          `- recast: ${requirePackage("recast").version}\n`,
+        ].join("\n");
+      },
+    },
+    stdin: {
+      display_index: 14,
+      help: "read file/directory list from stdin",
+      flag: true,
+      default: false,
+    },
+  });

src/utils/getArgsWithUpdatedTransformFile.ts

@@ -1,5 +1,4 @@
-export * from "./getArgsWithUpdatedTransformFile";
 export * from "./getHelpParagraph";
-export * from "./getTransformFileFromArgs";
+export * from "./getJsCodeshiftParser";
 export * from "./getTransforms";
 export * from "./getUpdatedTransformFile";