From e7a90581c2e7dba2047e38b9108462e0f5f4fbdd Mon Sep 17 00:00:00 2001
From: Luca Forstner <luca.forstner@sentry.io>
Date: Tue, 27 Sep 2022 09:26:15 +0000
Subject: [PATCH] ref(nextjs): Make `isBuild` rely on `NEXT_PHASE` environment
 variable

---
 packages/nextjs/src/utils/isBuild.ts       | 25 ++++-------
 packages/nextjs/test/utils/isBuild.test.ts | 51 ----------------------
 2 files changed, 8 insertions(+), 68 deletions(-)
 delete mode 100644 packages/nextjs/test/utils/isBuild.test.ts

diff --git a/packages/nextjs/src/utils/isBuild.ts b/packages/nextjs/src/utils/isBuild.ts
index 2e849807d8dd..609c6fbb41a8 100644
--- a/packages/nextjs/src/utils/isBuild.ts
+++ b/packages/nextjs/src/utils/isBuild.ts
@@ -2,21 +2,12 @@
  * Decide if the currently running process is part of the build phase or happening at runtime.
  */
 export function isBuild(): boolean {
-  // During build, the main process is invoked by
-  //   `node next build`
-  // and child processes are invoked as
-  //   `node <path>/node_modules/.../jest-worker/processChild.js`.
-  // The former is (obviously) easy to recognize, but the latter could happen at runtime as well. Fortunately, the main
-  // process hits this file before any of the child processes do, so we're able to set an env variable which the child
-  // processes can then check. During runtime, the main process is invoked as
-  //   `node next start`
-  // or
-  //   `node /var/runtime/index.js`,
-  // so we never drop into the `if` in the first place.
-  if (process.argv.includes('build') || process.env.SENTRY_BUILD_PHASE) {
-    process.env.SENTRY_BUILD_PHASE = 'true';
-    return true;
-  }
-
-  return false;
+  // Next.js sets the `NEXT_PHASE` env var depending on what phase/environment we're in.
+  // These phases are constants within the Next.js codebase but sadly they're not exported in a way that we can easily
+  // import them with our rollup setup so we're simply vendoring the relevant constant ourselves.
+  // This constant hasn't changed in the Next.js codebase since next@10:
+  // Most recent: https://github.com/vercel/next.js/blob/406d69d4d9f7d14b9bf497a134f0151914b13964/packages/next/shared/lib/constants.ts#L20
+  // v10: https://github.com/vercel/next.js/blob/118ab7992bc8f7a7e5a7bb996510d9b56ffe4f68/packages/next/next-server/lib/constants.ts#L2
+  const PHASE_PRODUCTION_BUILD = 'phase-production-build';
+  return process.env.NEXT_PHASE === PHASE_PRODUCTION_BUILD;
 }
diff --git a/packages/nextjs/test/utils/isBuild.test.ts b/packages/nextjs/test/utils/isBuild.test.ts
deleted file mode 100644
index 0bc1523b041a..000000000000
--- a/packages/nextjs/test/utils/isBuild.test.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-import { isBuild } from '../../src/utils/isBuild';
-
-let originalEnv: typeof process.env;
-let originalArgv: typeof process.argv;
-
-function assertNoMagicValues(): void {
-  if (Object.keys(process.env).includes('SENTRY_BUILD_PHASE') || process.argv.includes('build')) {
-    throw new Error('Not starting test with a clean setup');
-  }
-}
-
-describe('isBuild()', () => {
-  beforeEach(() => {
-    assertNoMagicValues();
-    originalEnv = { ...process.env };
-    originalArgv = [...process.argv];
-  });
-
-  afterEach(() => {
-    process.env = originalEnv;
-    process.argv = originalArgv;
-    assertNoMagicValues();
-  });
-
-  it("detects 'build' in argv", () => {
-    // the result of calling `next build`
-    process.argv = ['/abs/path/to/node', '/abs/path/to/nextjs/excecutable', 'build'];
-    expect(isBuild()).toBe(true);
-  });
-
-  it("sets env var when 'build' in argv", () => {
-    // the result of calling `next build`
-    process.argv = ['/abs/path/to/node', '/abs/path/to/nextjs/excecutable', 'build'];
-    isBuild();
-    expect(Object.keys(process.env).includes('SENTRY_BUILD_PHASE')).toBe(true);
-  });
-
-  it("does not set env var when 'build' not in argv", () => {
-    isBuild();
-    expect(Object.keys(process.env).includes('SENTRY_BUILD_PHASE')).toBe(false);
-  });
-
-  it('detects env var', () => {
-    process.env.SENTRY_BUILD_PHASE = 'true';
-    expect(isBuild()).toBe(true);
-  });
-
-  it("returns false when 'build' not in `argv` and env var not present", () => {
-    expect(isBuild()).toBe(false);
-  });
-});