filter minor nixpkgs updates

README.md

@@ -1,3 +1,12 @@
+# THIS IS A BAD FORK
+
+> [!CAUTION]
+> This is a fork of the awesome [nix-diff-action](https://github.com/natsukium/nix-diff-action). My fork contains changes that fit my workflow, but break expected behaviour for others. To make it worse, these changes are not gated by configuration options. To make it even worse, some of these changes are vibecoded. **DO NOT USE IN PRODUCTION**. Instead, use the original [nix-diff-action](https://github.com/natsukium/nix-diff-action).
+
+Below this line is the original README.md content at the time of forking.
+
+---
+
 # nix-diff-action
 
 A GitHub Action to compare Nix derivations between base and PR branches using [dix](https://github.com/faukah/dix).

dist/index.js

@@ -62022,6 +62022,35 @@ const hasPackageChanges = (diff) => {
 	if (!diff || diff.trim() === "") return false;
 	return diff.split(/\r?\n/).length > 5;
 };
+var isNixpkgsMinorUpdateLine = (line) => {
+	const match$3 = line.match(/^\[([A-Z.]+)\]\s+(\S+)\s+(.+?)\s+->\s+(.+)$/);
+	if (!match$3) return false;
+	if (match$3[1] !== "U.") return false;
+	const packageName = match$3[2];
+	if (!packageName.startsWith("nixos-system-") && packageName !== "darwin-system") return false;
+	const beforeVersion = match$3[3].trim();
+	const afterVersion = match$3[4].trim();
+	if (beforeVersion.includes(",") || afterVersion.includes(",")) return false;
+	if (!beforeVersion.endsWith(".drv") || !afterVersion.endsWith(".drv")) return false;
+	const extractMajorMinor = (version$1) => {
+		const versionMatch = version$1.match(/^(\d+\.\d+)\..+\.drv$/);
+		return versionMatch ? versionMatch[1] : null;
+	};
+	const beforeMajorMinor = extractMajorMinor(beforeVersion);
+	const afterMajorMinor = extractMajorMinor(afterVersion);
+	return beforeMajorMinor !== null && afterMajorMinor !== null && beforeMajorMinor === afterMajorMinor;
+};
+const filterNixpkgsMinorUpdates = (diff) => {
+	if (!diff || diff.trim() === "") return diff;
+	const filteredLines = diff.split(/\r?\n/).filter((line) => !isNixpkgsMinorUpdateLine(line));
+	const output = [];
+	for (let i = 0; i < filteredLines.length; i += 1) {
+		const line = filteredLines[i];
+		if (line.trim() === "CHANGED" && filteredLines[i + 1]?.trim() === "") continue;
+		output.push(line);
+	}
+	return output.join("\n");
+};
 var NIX_DIFF_ACTION_MARKER_BASE = "<!-- nix-diff-action";
 var getNixDiffActionMarker = (displayName) => displayName ? `${NIX_DIFF_ACTION_MARKER_BASE}:${displayName} -->` : `${NIX_DIFF_ACTION_MARKER_BASE} -->`;
 var MAX_COMMENT_LENGTH = 6e4;
@@ -68149,7 +68178,7 @@ var processNixOutput = (config, baseFlakeRef, prFlakeRef, baseSha, headSha, buil
 	});
 	yield* logInfo(`Base path: ${basePath}`);
 	yield* logInfo(`PR path: ${prPath}`);
-	const diff = yield* nix.getDixDiff(basePath, prPath, worktreePath);
+	const diff = filterNixpkgsMinorUpdates(yield* nix.getDixDiff(basePath, prPath, worktreePath));
 	return {
 		displayName: config.displayName,
 		attributePath: config.attribute,

src/main.test.ts

@@ -5,7 +5,7 @@ import { parseCommentStrategy, parseAttributes, validateDirectory } from "./prog
 import { processDiffResults } from "./programs/full.js";
 import { GitService, sanitizeBranchName } from "./services/git.js";
 import { NixService } from "./services/nix.js";
-import { hasDixChanges, hasPackageChanges } from "./services/utils.js";
+import { hasDixChanges, hasPackageChanges, filterNixpkgsMinorUpdates } from "./services/utils.js";
 import { createArtifactName } from "./services/artifact.js";
 
 describe("parseAttributes", () => {
@@ -632,6 +632,76 @@ describe("createArtifactName", () => {
   });
 });
 
+describe("filterNixpkgsMinorUpdates", () => {
+  test("removes nixos-system entries when major/minor is unchanged", () => {
+    const diff = `<<< /nix/store/old-nixos-system-eule-26.05.20251225.3e2499d.drv
+>>> /nix/store/new-nixos-system-eule-26.05.20251228.c0b0e0f.drv
+
+CHANGED
+[U.] nixos-system-eule 26.05.20251225.3e2499d.drv -> 26.05.20251228.c0b0e0f.drv
+[U.] hello 1.0.drv -> 1.1.drv
+
+SIZE: 10.0 MiB -> 10.0 MiB
+DIFF: 100 KiB`;
+    const result = filterNixpkgsMinorUpdates(diff);
+    expect(result).not.toContain("nixos-system-eule 26.05.20251225.3e2499d.drv");
+    expect(result).toContain("[U.] hello 1.0.drv -> 1.1.drv");
+  });
+
+  test("removes darwin-system entries when major/minor is unchanged", () => {
+    const diff = `<<< /nix/store/old-darwin-system-26.05.c2b3620.drv
+>>> /nix/store/new-darwin-system-26.05.d9a1b77.drv
+
+CHANGED
+[U.] darwin-system 26.05.c2b3620.drv -> 26.05.d9a1b77.drv
+
+SIZE: 260 MiB -> 260 MiB
+DIFF: 32 bytes`;
+    const result = filterNixpkgsMinorUpdates(diff);
+    expect(result).not.toContain("darwin-system 26.05.c2b3620.drv");
+  });
+
+  test("keeps nixos-system entries when major/minor changes", () => {
+    const diff = `<<< /nix/store/old-nixos-system-eule-25.11.20251101.aaaaaaa.drv
+>>> /nix/store/new-nixos-system-eule-26.05.20251228.bbbbbbb.drv
+
+CHANGED
+[U.] nixos-system-eule 25.11.20251101.aaaaaaa.drv -> 26.05.20251228.bbbbbbb.drv
+
+SIZE: 10.0 MiB -> 12.0 MiB
+DIFF: 200 KiB`;
+    const result = filterNixpkgsMinorUpdates(diff);
+    expect(result).toContain("nixos-system-eule 25.11.20251101.aaaaaaa.drv");
+  });
+
+  test("keeps nixos-system entries when status is not [U.]", () => {
+    const diff = `<<< /nix/store/old-nixos-system-eule-26.05.20251225.3e2499d.drv
+>>> /nix/store/new-nixos-system-eule-26.05.20251228.c0b0e0f.drv
+
+CHANGED
+[D.] nixos-system-eule 26.05.20251225.3e2499d.drv -> 26.05.20251228.c0b0e0f.drv
+
+SIZE: 10.0 MiB -> 10.0 MiB
+DIFF: 100 KiB`;
+    const result = filterNixpkgsMinorUpdates(diff);
+    expect(result).toContain("[D.] nixos-system-eule");
+  });
+
+  test("removes empty CHANGED section after filtering", () => {
+    const diff = `<<< /nix/store/old-nixos-system-eule-26.05.20251225.3e2499d.drv
+>>> /nix/store/new-nixos-system-eule-26.05.20251228.c0b0e0f.drv
+
+CHANGED
+[U.] nixos-system-eule 26.05.20251225.3e2499d.drv -> 26.05.20251228.c0b0e0f.drv
+
+SIZE: 10.0 MiB -> 10.0 MiB
+DIFF: -248 bytes`;
+    const result = filterNixpkgsMinorUpdates(diff);
+    expect(result).not.toContain("\nCHANGED\n");
+    expect(result).toContain("SIZE: 10.0 MiB -> 10.0 MiB");
+  });
+});
+
 describe("hasDixChanges", () => {
   test("returns false for undefined", () => {
     expect(hasDixChanges(undefined)).toBe(false);

src/programs/full.ts

@@ -23,6 +23,7 @@ import {
   postComment,
   setDiffOutput,
 } from "./shared.js";
+import { filterNixpkgsMinorUpdates } from "../services/utils.js";
 
 // Error type aliases for better readability
 type DiffError = NixPathInfoError | NixBuildError | NixDixError;
@@ -75,7 +76,8 @@ const processNixOutput = (
     yield* Effect.logInfo(`Base path: ${basePath}`);
     yield* Effect.logInfo(`PR path: ${prPath}`);
 
-    const diff = yield* nix.getDixDiff(basePath, prPath, worktreePath);
+    const rawDiff = yield* nix.getDixDiff(basePath, prPath, worktreePath);
+    const diff = filterNixpkgsMinorUpdates(rawDiff);
 
     return {
       displayName: config.displayName,

src/services/utils.ts

@@ -32,6 +32,58 @@ export const hasPackageChanges = (diff: string | undefined): boolean => {
   return lines.length > 5;
 };
 
+// WARNING: Shamefully vibecoded
+const isNixpkgsMinorUpdateLine = (line: string): boolean => {
+  const match = line.match(/^\[([A-Z.]+)\]\s+(\S+)\s+(.+?)\s+->\s+(.+)$/);
+  if (!match) return false;
+
+  const status = match[1];
+  if (status !== "U.") return false;
+
+  const packageName = match[2];
+  if (!packageName.startsWith("nixos-system-") && packageName !== "darwin-system") {
+    return false;
+  }
+
+  const beforeVersion = match[3].trim();
+  const afterVersion = match[4].trim();
+
+  if (beforeVersion.includes(",") || afterVersion.includes(",")) return false;
+  if (!beforeVersion.endsWith(".drv") || !afterVersion.endsWith(".drv")) return false;
+
+  const extractMajorMinor = (version: string): string | null => {
+    const versionMatch = version.match(/^(\d+\.\d+)\..+\.drv$/);
+    return versionMatch ? versionMatch[1] : null;
+  };
+
+  const beforeMajorMinor = extractMajorMinor(beforeVersion);
+  const afterMajorMinor = extractMajorMinor(afterVersion);
+
+  return (
+    beforeMajorMinor !== null && afterMajorMinor !== null && beforeMajorMinor === afterMajorMinor
+  );
+};
+
+// WARNING: Shamefully vibecoded
+export const filterNixpkgsMinorUpdates = (diff: string): string => {
+  if (!diff || diff.trim() === "") return diff;
+
+  const lines = diff.split(/\r?\n/);
+  const filteredLines = lines.filter((line) => !isNixpkgsMinorUpdateLine(line));
+  const output: string[] = [];
+
+  for (let i = 0; i < filteredLines.length; i += 1) {
+    const line = filteredLines[i];
+    if (line.trim() === "CHANGED" && filteredLines[i + 1]?.trim() === "") {
+      continue;
+    }
+
+    output.push(line);
+  }
+
+  return output.join("\n");
+};
+
 // Git utilities
 export { sanitizeBranchName } from "./git.js";