build: allow auto-discover all typings files in npm package by ts-api-guardian (#35691)

Adds a new feature to ts-api-guardian allowing for automatically discovering all
entry point d.ts files from all package.json files in a provided directory.

PR Close #35691

tools/ts-api-guardian/lib/cli.ts

@@ -14,7 +14,7 @@ const chalk = require('chalk');
 import * as minimist from 'minimist';
 import * as path from 'path';
 
-import {SerializationOptions, generateGoldenFile, verifyAgainstGoldenFile} from './main';
+import {SerializationOptions, generateGoldenFile, verifyAgainstGoldenFile, discoverAllEntrypoints} from './main';
 
 const CMD = 'ts-api-guardian';
 
@@ -46,6 +46,15 @@ export function startCli() {
     };
   }
 
+  // In autoDiscoverEntrypoints mode we set the inputed files as the discovered entrypoints
+  // for the rootDir
+  let entrypoints: string[];
+  if (argv['autoDiscoverEntrypoints']) {
+    entrypoints = discoverAllEntrypoints(argv['rootDir']);
+  } else {
+    entrypoints = argv._.slice();
+  }
+
   for (const error of errors) {
     console.warn(error);
   }
@@ -53,7 +62,7 @@ export function startCli() {
   if (mode === 'help') {
     printUsageAndExit(!!errors.length);
   } else {
-    const targets = resolveFileNamePairs(argv, mode);
+    const targets = resolveFileNamePairs(argv, mode, entrypoints);
 
     if (mode === 'out') {
       for (const {entrypoint, goldenFile} of targets) {
@@ -110,7 +119,7 @@ export function parseArguments(input: string[]):
       'allowModuleIdentifiers'
     ],
     boolean: [
-      'help', 'useAngularTagRules',
+      'help', 'useAngularTagRules', 'autoDiscoverEntrypoints',
       // Options used by chalk automagically
       'color', 'no-color'
     ],
@@ -147,15 +156,26 @@ export function parseArguments(input: string[]):
     modes.push('verify');
   }
 
-  if (!argv._.length) {
-    errors.push('No input file specified.');
-    modes = ['help'];
-  } else if (modes.length !== 1) {
-    errors.push('Specify either --out[Dir] or --verify[Dir]');
-    modes = ['help'];
-  } else if (argv._.length > 1 && !argv['outDir'] && !argv['verifyDir']) {
-    errors.push(`More than one input specified. Use --${modes[0]}Dir instead.`);
-    modes = ['help'];
+  if (argv['autoDiscoverEntrypoints']) {
+    if (!argv['rootDir']) {
+      errors.push(`--rootDir must be provided with --autoDiscoverEntrypoints.`);
+      modes = ['help'];
+    }
+    if (!argv['outDir'] && !argv['verifyDir']) {
+      errors.push(`--outDir or --verifyDir must be used with --autoDiscoverEntrypoints.`);
+      modes = ['help'];
+    }
+  } else {
+    if (!argv._.length) {
+      errors.push('No input file specified.');
+      modes = ['help'];
+    } else if (modes.length !== 1) {
+      errors.push('Specify either --out[Dir] or --verify[Dir]');
+      modes = ['help'];
+    } else if (argv._.length > 1 && !argv['outDir'] && !argv['verifyDir']) {
+      errors.push(`More than one input specified. Use --${modes[0]}Dir instead.`);
+      modes = ['help'];
+    }
   }
 
   return {argv, mode: modes[0], errors};
@@ -184,7 +204,8 @@ Options:
         --useAngularTagRules <boolean>  Whether the Angular specific tag rules should be used.
         --stripExportPattern <regexp>   Do not output exports matching the pattern
         --allowModuleIdentifiers <identifier>
-                                        Allow identifier for "* as foo" imports`);
+                                        Allow identifier for "* as foo" imports
+        --autoDiscoverEntrypoints       Automatically find all entrypoints .d.ts files in the rootDir`);
   process.exit(error ? 1 : 0);
 }
 
@@ -199,24 +220,31 @@ function resolveBazelFilePath(fileName: string): string {
   // are not available in the working directory. In order to resolve the real path for the
   // runfile, we need to use `require.resolve` which handles runfiles properly on Windows.
   if (process.env['BAZEL_TARGET']) {
-    return path.relative(process.cwd(), require.resolve(fileName));
+    // This try/catch block is necessary because if the path is to the source file directly
+    // rather than via symlinks in the bazel output directories, require is not able to
+    // resolve it.
+    try {
+      return path.relative(process.cwd(), require.resolve(fileName));
+    } catch (err) {
+      return path.relative(process.cwd(), fileName);
+    }
   }
 
   return fileName;
 }
 
-function resolveFileNamePairs(
-    argv: minimist.ParsedArgs, mode: string): {entrypoint: string, goldenFile: string}[] {
+function resolveFileNamePairs(argv: minimist.ParsedArgs, mode: string, entrypoints: string[]):
+    {entrypoint: string, goldenFile: string}[] {
   if (argv[mode]) {
     return [{
-      entrypoint: resolveBazelFilePath(argv._[0]),
+      entrypoint: resolveBazelFilePath(entrypoints[0]),
       goldenFile: resolveBazelFilePath(argv[mode]),
     }];
   } else {  // argv[mode + 'Dir']
     let rootDir = argv['rootDir'] || '.';
     const goldenDir = argv[mode + 'Dir'];
 
-    return argv._.map((fileName: string) => {
+    return entrypoints.map((fileName: string) => {
       return {
         entrypoint: resolveBazelFilePath(fileName),
         goldenFile: resolveBazelFilePath(path.join(goldenDir, path.relative(rootDir, fileName))),