[install] fix duplicate check on `peerDependencies` (#2039)

fixes #2037

2 files changed, 53 insertions, 9 deletions

diff --git a/src/install/lockfile.zig b/src/install/lockfile.zig
index 70e14fb82..e96a7be80 100644
--- a/src/install/lockfile.zig
+++ b/src/install/lockfile.zig
@@ -983,11 +983,10 @@ pub const Printer = struct {
                 var dep_id = resolutions_list[0].off;
                 const dep_end = dep_id + resolutions_list[0].len;
                 outer: while (dep_id < dep_end) : (dep_id += 1) {
+                    const dependency = dependencies_buffer[dep_id];
+                    if (dependency.behavior.isPeer()) continue;
                     const package_id = resolutions_buffer[dep_id];
                     if (package_id >= end) continue;
-                    const is_new = installed.isSet(package_id);
-
-                    const dependency = dependencies_buffer[dep_id];
                     const package_name = dependency.name.slice(string_buf);
 
                     if (this.updates.len > 0) {
@@ -1004,7 +1003,7 @@ pub const Printer = struct {
                         }
                     }
 
-                    if (!is_new) continue;
+                    if (!installed.isSet(package_id)) continue;
 
                     const fmt = comptime brk: {
                         if (enable_ansi_colors) {
@@ -1024,9 +1023,9 @@ pub const Printer = struct {
                 }
             } else {
                 outer: for (dependencies_buffer) |dependency, dep_id| {
+                    if (dependency.behavior.isPeer()) continue;
                     const package_id = resolutions_buffer[dep_id];
                     if (package_id >= end) continue;
-
                     const package_name = dependency.name.slice(string_buf);
 
                     if (this.updates.len > 0) {
@@ -1058,8 +1057,7 @@ pub const Printer = struct {
                 try writer.writeAll("\n");
             }
 
-            for (this.updates) |_, update_id| {
-                const dependency_id = id_map[update_id];
+            for (id_map) |dependency_id| {
                 if (dependency_id == invalid_package_id) continue;
                 const name = dependencies_buffer[dependency_id].name;
                 const package_id = resolutions_buffer[dependency_id];
@@ -2413,7 +2411,8 @@ pub const Package = extern struct {
             .version = dependency_version,
         };
 
-        if (comptime features.check_for_duplicate_dependencies) {
+        // peerDependencies may be specified on on existing dependencies
+        if (comptime features.check_for_duplicate_dependencies and !group.behavior.isPeer()) {
             var entry = lockfile.scratch.duplicate_checker_map.getOrPutAssumeCapacity(external_name.hash);
             if (entry.found_existing) {
                 // duplicate dependencies are allowed in optionalDependencies
diff --git a/test/bun.js/install/bun-install.test.ts b/test/bun.js/install/bun-install.test.ts
index 063cd3720..8cd826615 100644
--- a/test/bun.js/install/bun-install.test.ts
+++ b/test/bun.js/install/bun-install.test.ts
@@ -1685,7 +1685,6 @@ it("should consider peerDependencies during hoisting", async () => {
   expect(out.replace(/\s*\[[0-9\.]+m?s\]\s*$/, "").split(/\r?\n/)).toEqual([
     " + bar@workspace:bar",
     " + moo@workspace:moo",
-    " + baz@0.0.5",
     "",
     " 4 packages installed",
   ]);
@@ -1721,3 +1720,49 @@ it("should consider peerDependencies during hoisting", async () => {
   expect(await readdirSorted(join(package_dir, "moo"))).toEqual(["package.json"]);
   await access(join(package_dir, "bun.lockb"));
 });
+
+it("should not regard peerDependencies declarations as duplicates", async () => {
+  const urls: string[] = [];
+  setHandler(dummyRegistry(urls));
+  await writeFile(
+    join(package_dir, "package.json"),
+    JSON.stringify({
+      name: "foo",
+      version: "0.0.1",
+      dependencies: {
+        bar: "*",
+      },
+      peerDependencies: {
+        bar: "^0.0.2",
+      },
+    }),
+  );
+  const { stdout, stderr, exited } = spawn({
+    cmd: [bunExe(), "install", "--config", import.meta.dir + "/basic.toml"],
+    cwd: package_dir,
+    stdout: null,
+    stdin: "pipe",
+    stderr: "pipe",
+    env,
+  });
+  expect(stderr).toBeDefined();
+  const err = await new Response(stderr).text();
+  expect(err).toContain("Saved lockfile");
+  expect(stdout).toBeDefined();
+  const out = await new Response(stdout).text();
+  expect(out.replace(/\s*\[[0-9\.]+m?s\]\s*$/, "").split(/\r?\n/)).toEqual([
+    " + bar@0.0.2",
+    "",
+    " 1 packages installed",
+  ]);
+  expect(await exited).toBe(0);
+  expect(urls.sort()).toEqual([`${root_url}/bar`, `${root_url}/bar-0.0.2.tgz`]);
+  expect(requested).toBe(2);
+  expect(await readdirSorted(join(package_dir, "node_modules"))).toEqual([".cache", "bar"]);
+  expect(await readdirSorted(join(package_dir, "node_modules", "bar"))).toEqual(["package.json"]);
+  expect(await file(join(package_dir, "node_modules", "bar", "package.json")).json()).toEqual({
+    name: "bar",
+    version: "0.0.2",
+  });
+  await access(join(package_dir, "bun.lockb"));
+});