[cli] Store build error in "builds.json" file in vc build (#8148)

When a build fails, store the serialized Error in the "builds.json" file under the "build" object of the Builder that failed.

Example:

```json
{
  "//": "This file was generated by the `vercel build` command. It is not part of the Build Output API.",
  "target": "preview",
  "argv": [
    "/usr/local/bin/node",
    "/Users/nrajlich/Code/vercel/vercel/packages/cli/src/index.ts",
    "build",
    "--cwd",
    "/Users/nrajlich/Downloads/vc-build-next-repro/"
  ],
  "builds": [
    {
      "require": "@vercel/next",
      "requirePath": "/Users/nrajlich/Code/vercel/vercel/packages/next/dist/index",
      "apiVersion": 2,
      "src": "package.json",
      "use": "@vercel/next",
      "config": {
        "zeroConfig": true,
        "framework": "nextjs"
      },
      "error": {
        "name": "Error",
        "message": "Command \"pnpm run build\" exited with 1",
        "stack": "Error: Command \"pnpm run build\" exited with 1\n    at ChildProcess.<anonymous> (/Users/nrajlich/Code/vercel/vercel/packages/build-utils/dist/index.js:20591:20)\n    at ChildProcess.emit (node:events:527:28)\n    at ChildProcess.emit (node:domain:475:12)\n    at maybeClose (node:internal/child_process:1092:16)\n    at Process.ChildProcess._handle.onexit (node:internal/child_process:302:5)",
        "hideStackTrace": true,
        "code": "BUILD_UTILS_SPAWN_1"
      }
    }
  ]
}
```

.prettierignore

@@ -1,4 +1,5 @@
 # https://prettier.io/docs/en/ignore.html
 
-# ignore this file with an intentional syntax error
+# ignore these files with an intentional syntax error
 packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-syntax.js
+packages/cli/test/fixtures/unit/commands/build/node-error/api/typescript.ts

packages/cli/src/commands/build.ts

@@ -52,6 +52,13 @@ import { sortBuilders } from '../util/build/sort-builders';
 
 type BuildResult = BuildResultV2 | BuildResultV3;
 
+interface SerializedBuilder extends Builder {
+  error?: Error;
+  require?: string;
+  requirePath?: string;
+  apiVersion: number;
+}
+
 const help = () => {
   return console.log(`
    ${chalk.bold(`${cli.logo} ${cli.name} build`)}
@@ -297,32 +304,36 @@ export default async function main(client: Client): Promise<number> {
   const ops: Promise<Error | void>[] = [];
 
   // Write the `detectedBuilders` result to output dir
-  ops.push(
+  const buildsJsonBuilds = new Map<Builder, SerializedBuilder>(
-    fs.writeJSON(
+    builds.map(build => {
-      join(outputDir, 'builds.json'),
+      const builderWithPkg = buildersWithPkgs.get(build.use);
-      {
+      if (!builderWithPkg) {
-        '//': 'This file was generated by the `vercel build` command. It is not part of the Build Output API.',
+        throw new Error(`Failed to load Builder "${build.use}"`);
-        target,
-        argv: process.argv,
-        builds: builds.map(build => {
-          const builderWithPkg = buildersWithPkgs.get(build.use);
-          if (!builderWithPkg) {
-            throw new Error(`Failed to load Builder "${build.use}"`);
-          }
-          const { builder, pkg: builderPkg } = builderWithPkg;
-          return {
-            require: builderPkg.name,
-            requirePath: builderWithPkg.path,
-            apiVersion: builder.version,
-            ...build,
-          };
-        }),
-      },
-      {
-        spaces: 2,
       }
-    )
+      const { builder, pkg: builderPkg } = builderWithPkg;
+      return [
+        build,
+        {
+          require: builderPkg.name,
+          requirePath: builderWithPkg.path,
+          apiVersion: builder.version,
+          ...build,
+        },
+      ];
+    })
   );
+  const buildsJson = {
+    '//': 'This file was generated by the `vercel build` command. It is not part of the Build Output API.',
+    target,
+    argv: process.argv,
+    builds: Array.from(buildsJsonBuilds.values()),
+  };
+  const buildsJsonPath = join(outputDir, 'builds.json');
+  const writeBuildsJsonPromise = fs.writeJSON(buildsJsonPath, buildsJson, {
+    spaces: 2,
+  });
+
+  ops.push(writeBuildsJsonPromise);
 
   // The `meta` config property is re-used for each Builder
   // invocation so that Builders can share state between
@@ -347,51 +358,72 @@ export default async function main(client: Client): Promise<number> {
     if (!builderWithPkg) {
       throw new Error(`Failed to load Builder "${build.use}"`);
     }
-    const { builder, pkg: builderPkg } = builderWithPkg;
 
-    const buildConfig: Config = {
+    try {
-      outputDirectory: project.settings.outputDirectory ?? undefined,
+      const { builder, pkg: builderPkg } = builderWithPkg;
-      ...build.config,
-      projectSettings: project.settings,
-      installCommand: project.settings.installCommand ?? undefined,
-      devCommand: project.settings.devCommand ?? undefined,
-      buildCommand: project.settings.buildCommand ?? undefined,
-      framework: project.settings.framework,
-      nodeVersion: project.settings.nodeVersion,
-    };
-    const buildOptions: BuildOptions = {
-      files: filesMap,
-      entrypoint: build.src,
-      workPath,
-      repoRootPath,
-      config: buildConfig,
-      meta,
-    };
-    output.debug(
-      `Building entrypoint "${build.src}" with "${builderPkg.name}"`
-    );
-    const buildResult = await builder.build(buildOptions);
 
-    // Store the build result to generate the final `config.json` after
+      const buildConfig: Config = {
-    // all builds have completed
+        outputDirectory: project.settings.outputDirectory ?? undefined,
-    buildResults.set(build, buildResult);
+        ...build.config,
+        projectSettings: project.settings,
+        installCommand: project.settings.installCommand ?? undefined,
+        devCommand: project.settings.devCommand ?? undefined,
+        buildCommand: project.settings.buildCommand ?? undefined,
+        framework: project.settings.framework,
+        nodeVersion: project.settings.nodeVersion,
+      };
+      const buildOptions: BuildOptions = {
+        files: filesMap,
+        entrypoint: build.src,
+        workPath,
+        repoRootPath,
+        config: buildConfig,
+        meta,
+      };
+      output.debug(
+        `Building entrypoint "${build.src}" with "${builderPkg.name}"`
+      );
+      const buildResult = await builder.build(buildOptions);
 
-    // Start flushing the file outputs to the filesystem asynchronously
+      // Store the build result to generate the final `config.json` after
-    ops.push(
+      // all builds have completed
-      writeBuildResult(
+      buildResults.set(build, buildResult);
-        outputDir,
+
-        buildResult,
+      // Start flushing the file outputs to the filesystem asynchronously
-        build,
+      ops.push(
-        builder,
+        writeBuildResult(
-        builderPkg,
+          outputDir,
-        vercelConfig?.cleanUrls
+          buildResult,
-      ).then(
+          build,
-        override => {
+          builder,
-          if (override) overrides.push(override);
+          builderPkg,
-        },
+          vercelConfig?.cleanUrls
-        err => err
+        ).then(
-      )
+          override => {
-    );
+            if (override) overrides.push(override);
+          },
+          err => err
+        )
+      );
+    } catch (err: any) {
+      await writeBuildsJsonPromise;
+
+      const buildJsonBuild = buildsJsonBuilds.get(build);
+      if (buildJsonBuild) {
+        buildJsonBuild.error = {
+          name: err.name,
+          message: err.message,
+          stack: err.stack,
+          ...err,
+        };
+
+        await fs.writeJSON(buildsJsonPath, buildsJson, {
+          spaces: 2,
+        });
+      }
+
+      return 1;
+    }
   }
 
   if (corepackShimDir) {

packages/cli/test/fixtures/unit/commands/build/node-error/.vercel/project.json

@@ -0,0 +1,7 @@
+{
+  "orgId": ".",
+  "projectId": ".",
+  "settings": {
+    "framework": null
+  }
+}

packages/cli/test/fixtures/unit/commands/build/node-error/api/es6.js

@@ -0,0 +1 @@
+export default (req, res) => res.end('Vercel');

packages/cli/test/fixtures/unit/commands/build/node-error/api/index.js

@@ -0,0 +1 @@
+module.exports = (req, res) => res.end('Vercel');

packages/cli/test/fixtures/unit/commands/build/node-error/api/mjs.mjs

@@ -0,0 +1 @@
+export default (req, res) => res.end('Vercel');

packages/cli/test/fixtures/unit/commands/build/node-error/api/typescript.ts

@@ -0,0 +1,4 @@
+import { IncomingMessage, ServerResponse } from 'http';
+
+// Intentional syntax error to make the build fail
+export default (req: IncomingMessage, res: ServerResponse => res.end('Vercel');

packages/cli/test/unit/commands/build.test.ts

@@ -589,8 +589,6 @@ describe('build', () => {
     const output = join(cwd, '.vercel/output');
     try {
       process.chdir(cwd);
-      client.stderr.pipe(process.stderr);
-      client.setArgv('build');
       const exitCode = await build(client);
       expect(exitCode).toEqual(0);
 
@@ -619,4 +617,30 @@ describe('build', () => {
       delete process.env.__VERCEL_BUILD_RUNNING;
     }
   });
+
+  it('should store Builder error in `builds.json`', async () => {
+    const cwd = fixture('node-error');
+    const output = join(cwd, '.vercel/output');
+    try {
+      process.chdir(cwd);
+      const exitCode = await build(client);
+      expect(exitCode).toEqual(1);
+
+      // `builds.json` contains "error" build
+      const builds = await fs.readJSON(join(output, 'builds.json'));
+      expect(builds.builds).toHaveLength(4);
+
+      const errorBuilds = builds.builds.filter((b: any) => 'error' in b);
+      expect(errorBuilds).toHaveLength(1);
+
+      expect(errorBuilds[0].error.name).toEqual('Error');
+      expect(errorBuilds[0].error.message).toMatch(`TS1005`);
+      expect(errorBuilds[0].error.message).toMatch(`',' expected.`);
+      expect(errorBuilds[0].error.hideStackTrace).toEqual(true);
+      expect(errorBuilds[0].error.code).toEqual('NODE_TYPESCRIPT_ERROR');
+    } finally {
+      process.chdir(originalCwd);
+      delete process.env.__VERCEL_BUILD_RUNNING;
+    }
+  });
 });