refactor(ivy): move ngcc into a higher level folder (#29092)

PR Close #29092

packages/compiler-cli/ngcc/src/main.ts

@@ -0,0 +1,87 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import * as path from 'canonical-path';
+import * as yargs from 'yargs';
+
+import {checkMarkerFile, writeMarkerFile} from './packages/build_marker';
+import {DependencyHost} from './packages/dependency_host';
+import {DependencyResolver} from './packages/dependency_resolver';
+import {EntryPointFormat} from './packages/entry_point';
+import {makeEntryPointBundle} from './packages/entry_point_bundle';
+import {EntryPointFinder} from './packages/entry_point_finder';
+import {Transformer} from './packages/transformer';
+
+export function mainNgcc(args: string[]): number {
+  const options =
+      yargs
+          .option('s', {
+            alias: 'source',
+            describe: 'A path to the root folder to compile.',
+            default: './node_modules'
+          })
+          .option('f', {
+            alias: 'formats',
+            array: true,
+            describe: 'An array of formats to compile.',
+            default: ['fesm2015', 'esm2015', 'fesm5', 'esm5']
+          })
+          .option('t', {
+            alias: 'target',
+            describe: 'A path to a root folder where the compiled files will be written.',
+            defaultDescription: 'The `source` folder.'
+          })
+          .help()
+          .parse(args);
+
+  const sourcePath: string = path.resolve(options['s']);
+  const formats: EntryPointFormat[] = options['f'];
+  const targetPath: string = options['t'] || sourcePath;
+
+  const transformer = new Transformer(sourcePath, targetPath);
+  const host = new DependencyHost();
+  const resolver = new DependencyResolver(host);
+  const finder = new EntryPointFinder(resolver);
+
+  try {
+    const {entryPoints} = finder.findEntryPoints(sourcePath);
+    entryPoints.forEach(entryPoint => {
+
+      // Are we compiling the Angular core?
+      const isCore = entryPoint.name === '@angular/core';
+
+      // We transform the d.ts typings files while transforming one of the formats.
+      // This variable decides with which of the available formats to do this transform.
+      // It is marginally faster to process via the flat file if available.
+      const dtsTransformFormat: EntryPointFormat = entryPoint.fesm2015 ? 'fesm2015' : 'esm2015';
+
+      formats.forEach(format => {
+        if (checkMarkerFile(entryPoint, format)) {
+          console.warn(`Skipping ${entryPoint.name} : ${format} (already built).`);
+          return;
+        }
+
+        const bundle =
+            makeEntryPointBundle(entryPoint, isCore, format, format === dtsTransformFormat);
+        if (bundle === null) {
+          console.warn(
+              `Skipping ${entryPoint.name} : ${format} (no entry point file for this format).`);
+        } else {
+          transformer.transform(entryPoint, isCore, bundle);
+        }
+
+        // Write the built-with-ngcc marker
+        writeMarkerFile(entryPoint, format);
+      });
+    });
+  } catch (e) {
+    console.error(e.stack || e.message);
+    return 1;
+  }
+
+  return 0;
+}