Implement process.env.npm_lifecycle_event (#3097)

* Update run_command.zig

* Update env.test.ts

* Add files via upload

* Update run-process-env.test.ts

* Update env.test.ts

* Update harness.ts

4 files changed, 80 insertions, 43 deletions

diff --git a/src/cli/run_command.zig b/src/cli/run_command.zig
index 17b12dcfb..24304f169 100644
--- a/src/cli/run_command.zig
+++ b/src/cli/run_command.zig
@@ -960,6 +960,7 @@ pub const RunCommand = struct {
         var ORIGINAL_PATH: string = "";
         var this_bundler: bundler.Bundler = undefined;
         var root_dir_info = try configureEnvForRun(ctx, &this_bundler, null, &ORIGINAL_PATH, log_errors, force_using_bun);
+        this_bundler.env.map.putDefault("npm_lifecycle_event", script_name_to_search) catch unreachable;
         if (root_dir_info.enclosing_package_json) |package_json| {
             if (package_json.scripts) |scripts| {
                 switch (script_name_to_search.len) {
diff --git a/test/cli/run/env.test.ts b/test/cli/run/env.test.ts
index 328162f0b..1a4ca7cb7 100644
--- a/test/cli/run/env.test.ts
+++ b/test/cli/run/env.test.ts
@@ -1,47 +1,5 @@
 import { describe, expect, test } from "bun:test";
-import os from "os";
-import fs from "fs";
-import path from "path";
-import { bunEnv, bunExe } from "harness";
-
-function tempDirWithFiles(basename: string, files: Record<string, string>) {
-  const dir = fs.mkdtempSync(path.join(os.tmpdir(), basename + "_"));
-  for (const [name, contents] of Object.entries(files)) {
-    fs.writeFileSync(path.join(dir, name), contents);
-  }
-  return dir;
-}
-
-function bunRun(file: string, env?: Record<string, string>) {
-  const result = Bun.spawnSync([bunExe(), file], {
-    cwd: path.dirname(file),
-    env: {
-      ...bunEnv,
-      NODE_ENV: undefined,
-      ...env,
-    },
-  });
-  if (!result.success) throw new Error(result.stderr.toString("utf8"));
-  return {
-    stdout: result.stdout.toString("utf8").trim(),
-    stderr: result.stderr.toString("utf8").trim(),
-  };
-}
-function bunTest(file: string, env?: Record<string, string>) {
-  const result = Bun.spawnSync([bunExe(), "test", path.basename(file)], {
-    cwd: path.dirname(file),
-    env: {
-      ...bunEnv,
-      NODE_ENV: undefined,
-      ...env,
-    },
-  });
-  if (!result.success) throw new Error(result.stderr.toString("utf8"));
-  return {
-    stdout: result.stdout.toString("utf8").trim(),
-    stderr: result.stderr.toString("utf8").trim(),
-  };
-}
+import { bunRun, bunTest, tempDirWithFiles } from "harness";
 
 describe(".env file is loaded", () => {
   test(".env", () => {
diff --git a/test/cli/run/run-process-env.test.ts b/test/cli/run/run-process-env.test.ts
new file mode 100644
index 000000000..d245ff80c
--- /dev/null
+++ b/test/cli/run/run-process-env.test.ts
@@ -0,0 +1,16 @@
+import { describe, expect, test } from "bun:test";
+import { bunRunAsScript, tempDirWithFiles } from "harness";
+
+describe("process.env", () => {
+  test("npm_lifecycle_event", () => {
+    const scriptName = 'start:dev';
+
+    const dir = tempDirWithFiles("processenv", {
+      "package.json": `{'scripts': {'${scriptName}': 'bun run index.ts'}}`,
+      "index.ts": "console.log(process.env.npm_lifecycle_event);",
+    });
+    
+    const { stdout } = bunRunAsScript(dir, scriptName);
+    expect(stdout).toBe(scriptName);
+  });
+});
diff --git a/test/harness.ts b/test/harness.ts
index bb27f53a4..72670156d 100644
--- a/test/harness.ts
+++ b/test/harness.ts
@@ -1,5 +1,8 @@
 import { gc as bunGC, unsafe } from "bun";
 import { heapStats } from "bun:jsc";
+import path from "path";
+import fs from 'fs';
+import os from 'os';
 
 export const bunEnv: any = {
   ...process.env,
@@ -75,3 +78,62 @@ export function hideFromStackTrace(block: CallableFunction) {
     writable: true,
   });
 }
+
+export function tempDirWithFiles(basename: string, files: Record<string, string>) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), basename + "_"));
+  for (const [name, contents] of Object.entries(files)) {
+    fs.writeFileSync(path.join(dir, name), contents);
+  }
+  return dir;
+}
+
+export function bunRun(file: string, env?: Record<string, string>) {
+  const result = Bun.spawnSync([bunExe(), file], {
+    cwd: path.dirname(file),
+    env: {
+      ...bunEnv,
+      NODE_ENV: undefined,
+      ...env,
+    },
+  });
+  if (!result.success) throw new Error(result.stderr.toString("utf8"));
+  return {
+    stdout: result.stdout.toString("utf8").trim(),
+    stderr: result.stderr.toString("utf8").trim(),
+  };
+}
+
+export function bunTest(file: string, env?: Record<string, string>) {
+  const result = Bun.spawnSync([bunExe(), "test", path.basename(file)], {
+    cwd: path.dirname(file),
+    env: {
+      ...bunEnv,
+      NODE_ENV: undefined,
+      ...env,
+    },
+  });
+  if (!result.success) throw new Error(result.stderr.toString("utf8"));
+  return {
+    stdout: result.stdout.toString("utf8").trim(),
+    stderr: result.stderr.toString("utf8").trim(),
+  };
+}
+
+export function bunRunAsScript(dir: string, script: string, env?: Record<string, string>) {
+  const result = Bun.spawnSync([bunExe(), `run`, `${script}`], {
+    cwd: dir,
+    env: {
+      ...bunEnv,
+      NODE_ENV: undefined,
+      ...env,
+    },
+  });
+
+  if (!result.success)
+      throw new Error(result.stderr.toString("utf8"));
+
+  return {
+    stdout: result.stdout.toString("utf8").trim(),
+    stderr: result.stderr.toString("utf8").trim(),
+  };
+}