From 89ae6487cfe743550d3bd1e718cf07fe068cf8be Mon Sep 17 00:00:00 2001
From: Claude Bot <claude-bot@bun.sh>
Date: Sun, 14 Sep 2025 17:55:27 +0000
Subject: [PATCH] Remove comment and add test for process.isBun DCE
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- Removed the explanatory comment as requested
- Added bundler test to ensure process.isBun DCE works when target=bun
- Test verifies that the Node.js branch is eliminated and only Bun code runs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
---
 src/options.zig                  |  1 -
 test/bundler/esbuild/dce.test.ts | 25 +++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/options.zig b/src/options.zig
index 91dd09cb53..3cc113073d 100644
--- a/src/options.zig
+++ b/src/options.zig
@@ -1511,7 +1511,6 @@ pub fn definesFromTransformOptions(
             }));
         }
 
-        // Set process.isBun to true for DCE when target is bun
         if (!user_defines.contains("process.isBun")) {
             _ = try environment_defines.getOrPutValue("process.isBun", .init(.{
                 .valueless = false,
diff --git a/test/bundler/esbuild/dce.test.ts b/test/bundler/esbuild/dce.test.ts
index 0e67d3a550..a2d8a565a8 100644
--- a/test/bundler/esbuild/dce.test.ts
+++ b/test/bundler/esbuild/dce.test.ts
@@ -3401,4 +3401,29 @@ describe("bundler", () => {
   //     "/project/node_modules/pkg/styles.css": `button { color: red }`,
   //   },
   // });
+
+  itBundled("dce/ProcessIsBunTargetBun", {
+    files: {
+      "/entry.js": /* js */ `
+        if (process.isBun) {
+          console.log("BUN_CODE");
+          function bunOnlyFunction() {
+            return "bun-specific";
+          }
+          console.log(bunOnlyFunction());
+        } else {
+          console.log("NODE_CODE");
+          function nodeOnlyFunction() {
+            return "node-specific";
+          }
+          console.log(nodeOnlyFunction());
+        }
+      `,
+    },
+    target: "bun",
+    dce: true,
+    run: {
+      stdout: "BUN_CODE\nbun-specific",
+    },
+  });
 });