From f1c17880481628d12a561b1b7c8739f5836bbec0 Mon Sep 17 00:00:00 2001
From: Isaac Guzman <ig2505@columbia.edu>
Date: Fri, 17 Jul 2026 15:49:06 -0400
Subject: [PATCH 1/2] Preserve existing code.json tags during metadata updates

---
 src/__tests__/unit/main.test.ts | 39 +++++++++++++++++++++++++++++++++
 src/helper.ts                   |  9 ++++++++
 src/main.ts                     | 13 +++++------
 3 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/src/__tests__/unit/main.test.ts b/src/__tests__/unit/main.test.ts
index 475666be..f938377e 100644
--- a/src/__tests__/unit/main.test.ts
+++ b/src/__tests__/unit/main.test.ts
@@ -109,6 +109,45 @@ describe("getMetaData", () => {
       URL: "https://github.com/upstream-owner/upstream-repo",
     });
   });
+
+  it("preserves existing tags that are not repository topics", async () => {
+    const deps = createMockDeps();
+    const helpers = createHelpers(deps);
+
+    const existing = {
+      ...validCodeJSON,
+      tags: ["featured"],
+    } as any;
+
+    const result = await getMetaData(helpers, deps, existing);
+
+    expect(result.tags).toEqual(
+      expect.arrayContaining(["test", "automation", "featured"]),
+    );
+  });
+
+  it("does not duplicate tags that already exist as repository topics", async () => {
+    const deps = createMockDeps();
+    const helpers = createHelpers(deps);
+
+    const existing = {
+      ...validCodeJSON,
+      tags: ["test", "featured"],
+    } as any;
+
+    const result = await getMetaData(helpers, deps, existing);
+
+    expect(result.tags).toEqual(["test", "automation", "featured"]);
+  });
+
+  it("uses repository topics when no existing code.json is present", async () => {
+    const deps = createMockDeps();
+    const helpers = createHelpers(deps);
+
+    const result = await getMetaData(helpers, deps, null);
+
+    expect(result.tags).toEqual(["test", "automation"]);
+  });
 });
 
 describe("runWithDeps", () => {
diff --git a/src/helper.ts b/src/helper.ts
index 57be7b12..39767d2c 100644
--- a/src/helper.ts
+++ b/src/helper.ts
@@ -334,6 +334,7 @@ export function createHelpers(deps: Dependencies) {
     readJSON,
     sendPR,
     pushDirectlyWithFallback,
+    mergeTags,
   };
 }
 
@@ -390,6 +391,14 @@ export function mergeReusedCode(
   return merged;
 }
 
+// combines repository topics with existing manually added tags, de-duped
+export function mergeTags(
+  repositoryTopics: string[] = [],
+  existingTags: string[] = [],
+): string[] {
+  return Array.from(new Set([...repositoryTopics, ...existingTags]));
+}
+
 function bodyOfPR(): string {
   return `
   ## Welcome to the Federal Open Source Community!
diff --git a/src/main.ts b/src/main.ts
index 496e5729..5ad790d1 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -112,12 +112,11 @@ async function getMetaData(
     ? partialCodeJSON.description
     : existingCodeJSON?.description || "";
 
-  // only update tags if we have new ones from GitHub Topics, otherwise keep existing
-  const shouldUpdateTags =
-    partialCodeJSON.tags && partialCodeJSON.tags.length > 0;
-  const tags = shouldUpdateTags
-    ? partialCodeJSON.tags
-    : existingCodeJSON?.tags || [];
+  // preserve existing tags and append repository topics, de-duped
+  const tags = helpers.mergeTags(
+    partialCodeJSON.tags ?? [],
+    existingCodeJSON?.tags ?? [],
+  );
 
   // handling legacy contractNumber that turned from string to array which caused validation errors
   let contractNumber: string[] = [];
@@ -135,7 +134,7 @@ async function getMetaData(
 
   if (deps.isArchived) {
     status = "Archival";
-    tags?.push("archived");
+    tags.push("archived");
   }
 
   // detect the fork upstream and government-made dependencies, then merge with any existing reusedCode

From bff836d9f811f352ddda29190223fd4fe3780aad Mon Sep 17 00:00:00 2001
From: Isaac Guzman <ig2505@columbia.edu>
Date: Fri, 17 Jul 2026 15:57:29 -0400
Subject: [PATCH 2/2] Fixed first test to pass without dupes

---
 src/__tests__/unit/main.test.ts | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/__tests__/unit/main.test.ts b/src/__tests__/unit/main.test.ts
index f938377e..2d8f872b 100644
--- a/src/__tests__/unit/main.test.ts
+++ b/src/__tests__/unit/main.test.ts
@@ -121,9 +121,7 @@ describe("getMetaData", () => {
 
     const result = await getMetaData(helpers, deps, existing);
 
-    expect(result.tags).toEqual(
-      expect.arrayContaining(["test", "automation", "featured"]),
-    );
+    expect(result.tags).toEqual(["test", "automation", "featured"]);
   });
 
   it("does not duplicate tags that already exist as repository topics", async () => {