test: add test case for static flag tree-shaking (#8476)

IWANABETHATGUY · web-flow · commit 456b9f2371bb · 2026-02-27T13:46:07.000+08:00
related to #7235
diff --git a/crates/rolldown/tests/rolldown/issues/7235/_config.json b/crates/rolldown/tests/rolldown/issues/7235/_config.json
@@ -0,0 +1,4 @@
+{
+  "_comment": "Test for issue #7235: Static flags imported from another file should be tree-shaken",
+  "config": {}
+}
diff --git a/crates/rolldown/tests/rolldown/issues/7235/_test.mjs b/crates/rolldown/tests/rolldown/issues/7235/_test.mjs
@@ -0,0 +1,12 @@
+import nodeFs from 'node:fs';
+import nodePath from 'node:path';
+import assert from 'node:assert';
+
+const distDir = nodePath.join(import.meta.dirname, 'dist');
+const mainFile = nodePath.join(distDir, 'main.js');
+const content = nodeFs.readFileSync(mainFile, 'utf8');
+
+// The dead branch should be eliminated by DCE
+assert(!content.includes('should not see me in bundle'), 'dead branch should be tree-shaken');
+// The live branch should remain
+assert(content.includes('flag is false correctly'), 'live branch should be kept');
diff --git a/crates/rolldown/tests/rolldown/issues/7235/artifacts.snap b/crates/rolldown/tests/rolldown/issues/7235/artifacts.snap
@@ -0,0 +1,12 @@
+---
+source: crates/rolldown_testing/src/integration_test.rs
+---
+# Assets
+
+## main.js
+
+```js
+console.log("flag is false correctly");
+//#endregion
+
+```
diff --git a/crates/rolldown/tests/rolldown/issues/7235/flags.js b/crates/rolldown/tests/rolldown/issues/7235/flags.js
@@ -0,0 +1 @@
+export const flag = false;
diff --git a/crates/rolldown/tests/rolldown/issues/7235/main.js b/crates/rolldown/tests/rolldown/issues/7235/main.js
@@ -0,0 +1,7 @@
+import { flag } from './flags.js';
+
+if (flag) {
+  console.log('should not see me in bundle!');
+} else {
+  console.log('flag is false correctly');
+}
diff --git a/crates/rolldown/tests/snapshots/integration_rolldown__filename_with_hash.snap b/crates/rolldown/tests/snapshots/integration_rolldown__filename_with_hash.snap
@@ -4931,6 +4931,10 @@ expression: output
 - middle-!~{003}~.js => middle-CMhJ5DMW.js
 - server-!~{002}~.js => server-DfC8g3sb.js
 
+# tests/rolldown/issues/7235
+
+- main-!~{000}~.js => main-Bo1PArHf.js
+
 # tests/rolldown/issues/7286
 
 - main-!~{000}~.js => main-2AMGYXtd.js

-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +{
 +  "_comment": "Test for issue #7235: Static flags imported from another file should be tree-shaken",
 +  "config": {}
 +}