feat(tools): minify proto JS files

package.json

@@ -29,7 +29,8 @@
     "proto3-json-serializer": "^1.0.0",
     "protobufjs": "7.2.2",
     "protobufjs-cli": "1.1.1",
-    "retry-request": "^5.0.0"
+    "retry-request": "^5.0.0",
+    "yargs": "^17.7.1"
   },
   "devDependencies": {
     "@compodoc/compodoc": "1.1.19",
@@ -42,6 +43,7 @@
     "@types/pumpify": "^1.4.1",
     "@types/sinon": "^10.0.0",
     "@types/uglify-js": "^3.17.0",
+    "@types/yargs": "^17.0.24",
     "c8": "^7.0.0",
     "codecov": "^3.1.0",
     "execa": "^5.0.0",

test/fixtures/echo.js

@@ -0,0 +1,28 @@
+/**
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Lots of comments we can delete in uglify
+async function main() {
+    // Showcases auto-pagination functionality.
+
+    // Let's say we have an API call that returns results grouped into pages.
+    // It accepts 4 parameters (just like gRPC stub calls do):
+    return 'SUCCESS';
+  }
+
+  main().catch(console.error);
+  // More comments
+

test/unit/minify.ts

@@ -48,4 +48,17 @@ describe('minify tool', () => {
     assert.deepEqual(objectBefore, objectAfter);
     assert.deepEqual(objectBefore, parsedObjectAfter);
   });
+
+  it('minifies the proto js file', async () => {
+    const echoProtoJsFixture = path.join(fixturesDir, 'echo.js');
+    const echoProtoJs = path.join(testDir, 'echo.js');
+    await fsp.copyFile(echoProtoJsFixture, echoProtoJs);
+    const statBefore = await fsp.stat(echoProtoJs);
+    const resultBefore = require(echoProtoJs);
+    await minify.main({directory: testDir, minifyJs: true});
+    const statAfter = await fsp.stat(echoProtoJs);
+    const resultAfter = require(echoProtoJs);
+    assert(statBefore.size > statAfter.size);
+    assert.deepEqual(resultBefore, resultAfter);
+  });
 });

tools/minify.ts

@@ -19,49 +19,70 @@
 import {promises as fsp} from 'fs';
 import * as path from 'path';
 import * as uglify from 'uglify-js';
+import * as yargs from 'yargs';
 
-async function minifyFile(filename: string) {
+interface CliArgs {
+  directory?: string;
+  minifyJs?: boolean;
+}
+async function minifyFile(filename: string, isJs: boolean) {
   const content = (await fsp.readFile(filename)).toString();
-  const output = uglify.minify(content, {
-    expression: true,
-    compress: false, // we need to keep it valid JSON
-    output: {quote_keys: true},
-  });
+  let output;
+  if (!isJs) {
+    output = uglify.minify(content, {
+      expression: true,
+      compress: false, // we need to keep it valid JSON
+      output: {quote_keys: true},
+    });
+  } else {
+    output = uglify.minify(content, {
+      expression: false,
+    });
+  }
   if (output.error) {
     throw output.error;
   }
   await fsp.writeFile(filename, output.code);
 }
 
-export async function main(directory?: string) {
-  const buildDir = directory ?? path.join(process.cwd(), 'build', 'protos');
+export async function main(args?: CliArgs | string | undefined) {
+  let buildDir;
+  if (typeof args === 'object' && args.directory) {
+    buildDir = args.directory;
+  } else if (typeof args === 'string') {
+    buildDir = args;
+  } else {
+    buildDir = path.join(process.cwd(), 'build', 'protos');
+  }
   const files = await fsp.readdir(buildDir);
   const jsonFiles = files.filter(file => file.match(/\.json$/));
   for (const jsonFile of jsonFiles) {
     console.log(`Minifying ${jsonFile}...`);
-    await minifyFile(path.join(buildDir, jsonFile));
+    await minifyFile(path.join(buildDir, jsonFile), false);
+  }
+  if (typeof args === 'object' && args?.minifyJs) {
+    const jsFiles = files.filter(file => file.match(/\.js$/));
+    for (const jsFile of jsFiles) {
+      console.log(`Minifying ${jsFile}...`);
+      await minifyFile(path.join(buildDir, jsFile), true);
+    }
   }
-  console.log('Minified all proto JSON files successfully.');
-}
-
-function usage() {
-  console.log(`Usage: node ${process.argv[1]} [directory]`);
-  console.log(
-    'Minifies all JSON files in-place in the given directory (non-recursively).'
-  );
   console.log(
-    'If no directory is given, minifies JSON files in ./build/protos.'
+    `Minified all proto ${
+      typeof args === 'object' && args?.minifyJs ? 'JS and JSON' : 'JSON'
+    } files successfully.`
   );
 }
 
 if (require.main === module) {
-  // argv[0] is node.js binary, argv[1] is script path
-
-  if (process.argv[2] === '--help') {
-    usage();
-    // eslint-disable-next-line no-process-exit
-    process.exit(1);
+  let args;
+  if (process.argv.length === 3 && !process.argv[2].includes('--directory')) {
+    args = process.argv[2] as string;
+  } else {
+    args = yargs(process.argv.slice(2)).usage(
+      `Usage: node ${process.argv[1]} [--directory] [--minifyJs]\nMinifies all JSON files in-place in the given directory (non-recursively).\nIf no directory is given, minifies JSON files in ./build/protos.\nCan minify JS files as well using --minifyJS flag`
+    ).argv as unknown as CliArgs;
   }
 
-  main(process.argv[2]);
+  main(args);
 }