fix(coding-agent): tighten skill discovery and edit diffs closes #2603

packages/coding-agent/test/package-manager.test.ts

@@ -106,6 +106,22 @@ Content`,
 			expect(result.skills.some((r) => r.path === skillFile && r.enabled)).toBe(true);
 		});
 
+		it("should auto-discover root markdown skills from .pi skill dirs", async () => {
+			const skillFile = join(agentDir, "skills", "single-file.md");
+			mkdirSync(join(agentDir, "skills"), { recursive: true });
+			writeFileSync(
+				skillFile,
+				`---
+name: single-file
+description: A root markdown skill
+---
+Content`,
+			);
+
+			const result = await packageManager.resolve();
+			expect(result.skills.some((r) => r.path === skillFile && r.enabled)).toBe(true);
+		});
+
 		it("should resolve project paths relative to .pi", async () => {
 			const extDir = join(tempDir, ".pi", "extensions");
 			mkdirSync(extDir, { recursive: true });
@@ -232,6 +248,26 @@ Content`,
 			expect(result.skills.some((r) => r.path === middleSkill && r.enabled)).toBe(true);
 		});
 
+		it("should ignore root markdown files in .agents/skills", async () => {
+			const agentsSkillsDir = join(tempDir, ".agents", "skills");
+			mkdirSync(join(agentsSkillsDir, "nested-skill"), { recursive: true });
+			const rootSkill = join(agentsSkillsDir, "root-file.md");
+			const nestedSkill = join(agentsSkillsDir, "nested-skill", "SKILL.md");
+			writeFileSync(rootSkill, "---\nname: root-file\ndescription: Root markdown file\n---\n");
+			writeFileSync(nestedSkill, "---\nname: nested-skill\ndescription: Nested skill\n---\n");
+
+			const pm = new DefaultPackageManager({
+				cwd: join(tempDir, "work"),
+				agentDir,
+				settingsManager,
+			});
+			mkdirSync(join(tempDir, "work"), { recursive: true });
+
+			const result = await pm.resolve();
+			expect(result.skills.some((r) => r.path === rootSkill)).toBe(false);
+			expect(result.skills.some((r) => r.path === nestedSkill && r.enabled)).toBe(true);
+		});
+
 		it("should keep ~/.agents/skills user-scoped when cwd is under home in a non-git directory", async () => {
 			const previousHome = process.env.HOME;
 			process.env.HOME = tempDir;
@@ -352,6 +388,19 @@ Content`,
 			expect(result.extensions.some((r) => pathEndsWith(r.path, "main.ts") && r.enabled)).toBe(true);
 			expect(result.themes.some((r) => pathEndsWith(r.path, "dark.json") && r.enabled)).toBe(true);
 		});
+
+		it("should stop recursing when a package skill directory contains SKILL.md", async () => {
+			const pkgDir = join(tempDir, "skill-root-pkg");
+			mkdirSync(join(pkgDir, "skills", "root-skill", "nested-skill"), { recursive: true });
+			const rootSkill = join(pkgDir, "skills", "root-skill", "SKILL.md");
+			const nestedSkill = join(pkgDir, "skills", "root-skill", "nested-skill", "SKILL.md");
+			writeFileSync(rootSkill, "---\nname: root-skill\ndescription: Root skill\n---\n");
+			writeFileSync(nestedSkill, "---\nname: nested-skill\ndescription: Nested skill\n---\n");
+
+			const result = await packageManager.resolveExtensionSources([pkgDir]);
+			expect(result.skills.some((r) => r.path === rootSkill && r.enabled)).toBe(true);
+			expect(result.skills.some((r) => r.path === nestedSkill)).toBe(false);
+		});
 	});
 
 	describe("progress callback", () => {

packages/coding-agent/test/tools.test.ts

@@ -277,6 +277,29 @@ describe("Coding Agent Tools", () => {
 			expect(result.details?.diff).toContain("GAMMA");
 		});
 
+		it("should collapse large unchanged gaps in multi-edit diffs", async () => {
+			const testFile = join(testDir, "edit-multi-large-gap.txt");
+			const lines = Array.from({ length: 600 }, (_, i) => `line ${String(i + 1).padStart(3, "0")}`);
+			writeFileSync(testFile, `${lines.join("\n")}\n`);
+
+			const result = await editTool.execute("test-call-8b", {
+				path: testFile,
+				edits: [
+					{ oldText: "line 100\n", newText: "LINE 100\n" },
+					{ oldText: "line 300\n", newText: "LINE 300\n" },
+					{ oldText: "line 500\n", newText: "LINE 500\n" },
+				],
+			});
+
+			const diff = result.details?.diff ?? "";
+			expect(diff).toContain("LINE 100");
+			expect(diff).toContain("LINE 300");
+			expect(diff).toContain("LINE 500");
+			expect(diff).toContain("...");
+			expect(diff).not.toContain("line 250");
+			expect(diff.split("\n").length).toBeLessThan(50);
+		});
+
 		it("should match edits against the original file, not incrementally", async () => {
 			const testFile = join(testDir, "edit-multi-original.txt");
 			writeFileSync(testFile, "foo\nbar\nbaz\n");