Placeholder for transforms with information in help (#12)

Author: trivikr

.changeset/pink-teachers-dress.md

@@ -0,0 +1,5 @@
+---
+"aws-sdk-js-codemod": patch
+---
+
+Adds a placeholder for transforms with information under help option

package.json

@@ -34,7 +34,8 @@
   },
   "dependencies": {
     "jscodeshift": "0.13.1",
-    "jscodeshift-find-imports": "2.0.4"
+    "jscodeshift-find-imports": "2.0.4",
+    "table": "6.8.0"
   },
   "devDependencies": {
     "@changesets/cli": "2.21.0",

src/cli.ts

@@ -5,10 +5,15 @@ import { spawn } from "child_process";
 // 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
+import { getHelpParagraph, getTransforms } from "./utils";
+
+export const run = async (args: string[]): Promise<void> => {
+  const transforms = getTransforms();
 
-export const run = async (args): Promise<void> => {
   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));
   }
   spawn("npm", ["exec", "jscodeshift", "--", ...args], {
     stdio: "inherit",

src/transforms/index.ts

@@ -0,0 +1 @@
+export * from "./types";

src/transforms/types.ts

@@ -0,0 +1,26 @@
+export type PositionalOptionsType = "boolean" | "number" | "string";
+
+export interface AwsSdkJsCodemodTransformOption {
+  /** array of values, limit valid option arguments to a predefined set */
+  choices?: ReadonlyArray<boolean> | ReadonlyArray<number> | ReadonlyArray<string>;
+
+  /** value, set a default value for the option */
+  default?: boolean | number | string;
+
+  /** string, the option description for help content */
+  description: string;
+
+  /** string, the type of the option */
+  type: PositionalOptionsType;
+}
+
+export interface AwsSdkJsCodemodTransform {
+  /** string, the name of the transform */
+  name: string;
+
+  /** string, the description of the transform for help content */
+  description: string;
+
+  /** array of TransformOption, the which can be passed to the transform */
+  options: AwsSdkJsCodemodTransformOption[];
+}

src/transforms/v2-to-v3/transform.ts

@@ -0,0 +1,8 @@
+export const name = "v2-to-v3";
+
+export const description =
+  "Converts AWS SDK for JavaScript APIs in a Javascript/TypeScript codebase" +
+  " from version 2 (v2) to version 3 (v3).";
+
+// Additional options will come here, like running on specific clients.
+export const options = [];

src/transforms/v2-to-v3/transformer.ts

@@ -0,0 +1,10 @@
+import { API, FileInfo } from "jscodeshift";
+
+export default function transformer(file: FileInfo, api: API) {
+  const j = api.jscodeshift;
+  const root = j(file.source);
+
+  // transform `root` here
+
+  return root.toSource();
+}

src/utils/getHelpParagraph.ts

@@ -0,0 +1,23 @@
+import { getBorderCharacters, table } from "table";
+
+import { AwsSdkJsCodemodTransform } from "../transforms";
+
+export const getHelpParagraph = (transforms: AwsSdkJsCodemodTransform[]) =>
+  `----------------------------------------------------------------------------------------------------
+aws-sdk-js-codemod is a lightweight wrapper over jscodeshift.
+It processes --help, --version and --transform options before passing them downstream.
+
+You can provide names of the custom transforms instead of a local path or url:
+
+${table(
+  transforms.map(({ name, description }) => [name, description]),
+  {
+    border: getBorderCharacters("void"),
+    columns: [
+      { width: 12, alignment: "right" },
+      { width: 88, wrapWord: true },
+    ],
+  }
+)}Example: aws-sdk-js-codemod -t v2-to-v3 example.js
+
+----------------------------------------------------------------------------------------------------\n\n`;

src/utils/getTransforms.ts

@@ -0,0 +1,13 @@
+import { readdirSync } from "fs";
+import { join } from "path";
+
+import { AwsSdkJsCodemodTransform } from "../transforms";
+
+export const getTransforms = () =>
+  readdirSync(join(__dirname, "..", "transforms"), { withFileTypes: true })
+    .filter((dirent) => dirent.isDirectory())
+    .map((dirent) => dirent.name)
+    .map((dirName) => {
+      const { name, description, options } = require(`../transforms/${dirName}/transform`); // eslint-disable-line
+      return { name, description, options } as AwsSdkJsCodemodTransform;
+    });

src/utils/index.ts

@@ -0,0 +1,2 @@
+export * from "./getHelpParagraph";
+export * from "./getTransforms";