From 5a674b95f1d081daa5a788e91a84d8eb45b96bcc Mon Sep 17 00:00:00 2001
From: Martin Hochel <martinhochel@microsoft.com>
Date: Tue, 10 Aug 2021 19:29:37 +0200
Subject: [PATCH] fix(scripts): resolve api-extractor execution issue within
 packages with new DX

---
 scripts/tasks/api-extractor.ts | 84 +++++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 2 deletions(-)

diff --git a/scripts/tasks/api-extractor.ts b/scripts/tasks/api-extractor.ts
index cd535ecbbdf395..e78fc410b69cb2 100644
--- a/scripts/tasks/api-extractor.ts
+++ b/scripts/tasks/api-extractor.ts
@@ -1,6 +1,10 @@
+import fs from 'fs';
 import * as glob from 'glob';
 import * as path from 'path';
-import { apiExtractorVerifyTask, task, series } from 'just-scripts';
+import jju from 'jju';
+import { apiExtractorVerifyTask, task, series, resolveCwd, logger, TscTaskOptions } from 'just-scripts';
+
+const noop = () => {};
 
 const apiExtractorConfigs = glob
   .sync(path.join(process.cwd(), 'config/api-extractor*.json'))
@@ -14,10 +18,86 @@ export function apiExtractor() {
   return apiExtractorConfigs.length
     ? series(
         ...apiExtractorConfigs.map(([configPath, configName]) => {
+          // note we have `"strictNullChecks": false,` turned off - so from TS point of view this always returns API 🚨
+          const overrideApi = overrideExtractorConfigForPackagesWithTsPathAliases({
+            apiExtractorConfigPath: configPath,
+            tsConfigPath: resolveCwd('./tsconfig.json'),
+          });
+
+          const cleanupOverrides = overrideApi ? overrideApi.resetConfig : () => noop;
+
           const taskName = `api-extractor:${configName}`;
-          task(taskName, apiExtractorVerifyTask({ configJsonFilePath: configPath, localBuild }));
+
+          task(
+            taskName,
+            series(
+              () => {
+                overrideApi && overrideApi.overrideConfig();
+              },
+              () => {
+                try {
+                  return apiExtractorVerifyTask({ configJsonFilePath: configPath, localBuild });
+                } catch (err) {
+                  cleanupOverrides();
+                  console.error(err);
+                  process.exit(1);
+                }
+              },
+              () => {
+                cleanupOverrides();
+              },
+            ),
+          );
+
           return taskName;
         }),
       )
     : 'no-op';
 }
+
+interface TsConfig {
+  extends?: string;
+
+  /**
+   * typescript doesn't provide a correct type for the compiler options file
+   * -> (typescript.CompilerOptions has enum values instead of raw options in some cases)
+   */
+  compilerOptions: TscTaskOptions;
+  include?: string[];
+  exclude?: string[];
+}
+
+function overrideExtractorConfigForPackagesWithTsPathAliases(options: {
+  tsConfigPath: string;
+  apiExtractorConfigPath: string;
+}) {
+  const tsConfig: TsConfig = jju.parse(fs.readFileSync(options.tsConfigPath, 'utf-8'));
+  const shouldOverrideConfig = Boolean(tsConfig.extends);
+
+  if (!shouldOverrideConfig) {
+    return null;
+  }
+
+  logger.info(`📣 API-EXTRACTOR: package is using TS path aliases. Overriding ts compiler settings for api-extractor.`);
+
+  const originalContent = fs.readFileSync(options.apiExtractorConfigPath, 'utf-8');
+  const apiExtractorConfigOriginal = jju.parse(originalContent, { mode: 'json' });
+
+  tsConfig.compilerOptions.baseUrl = '.';
+  apiExtractorConfigOriginal.compiler = {
+    overrideTsconfig: tsConfig,
+  };
+
+  const api = {
+    overrideConfig: () => {
+      const newContent = jju.update(originalContent, apiExtractorConfigOriginal, { mode: 'json', indent: 2 });
+
+      fs.writeFileSync(options.apiExtractorConfigPath, newContent, 'utf-8');
+    },
+    resetConfig: () => {
+      fs.writeFileSync(options.apiExtractorConfigPath, originalContent, 'utf-8');
+    },
+  };
+
+  return api;
+}