Squashed 'third_party/pi/' content from commit d981de122

git-subtree-dir: third_party/pi
git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

packages/coding-agent/test/system-prompt.test.ts

@@ -0,0 +1,170 @@
+import { describe, expect, test } from "vitest";
+import type { Skill } from "../src/core/skills.ts";
+import { createSyntheticSourceInfo } from "../src/core/source-info.ts";
+import { buildSystemPrompt } from "../src/core/system-prompt.ts";
+
+const testSkill: Skill = {
+	name: "test-skill",
+	description: "A test skill.",
+	filePath: "/skills/test-skill/SKILL.md",
+	baseDir: "/skills/test-skill",
+	sourceInfo: createSyntheticSourceInfo("/skills/test-skill/SKILL.md", { source: "test" }),
+	disableModelInvocation: false,
+};
+
+describe("buildSystemPrompt", () => {
+	describe("empty tools", () => {
+		test("shows (none) for empty tools list", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: [],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("Available tools:\n(none)");
+		});
+
+		test("shows file paths guideline even with no tools", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: [],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("Show file paths clearly");
+		});
+	});
+
+	describe("default tools", () => {
+		test("includes all default tools when snippets are provided", () => {
+			const prompt = buildSystemPrompt({
+				toolSnippets: {
+					read: "Read file contents",
+					bash: "Execute bash commands",
+					edit: "Make surgical edits",
+					write: "Create or overwrite files",
+				},
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("- read:");
+			expect(prompt).toContain("- bash:");
+			expect(prompt).toContain("- edit:");
+			expect(prompt).toContain("- write:");
+		});
+
+		test.each([
+			[["powershell"], "Use PowerShell for file operations"],
+			[["bash", "powershell"], "Use bash or PowerShell for file operations"],
+		] as const)("uses shell-specific guidance for %j", (selectedTools, expected) => {
+			const prompt = buildSystemPrompt({
+				selectedTools: [...selectedTools],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain(expected);
+		});
+
+		test("instructs models to resolve pi docs and examples under absolute base paths", () => {
+			const prompt = buildSystemPrompt({
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain(
+				"- When reading pi docs or examples, resolve docs/... under Additional docs and examples/... under Examples, not the current working directory",
+			);
+			expect(prompt).toContain("environment variables (docs/environment-variables.md)");
+		});
+	});
+
+	describe("custom tool snippets", () => {
+		test("includes custom tools in available tools section when promptSnippet is provided", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: ["read", "dynamic_tool"],
+				toolSnippets: {
+					dynamic_tool: "Run dynamic test behavior",
+				},
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("- dynamic_tool: Run dynamic test behavior");
+		});
+
+		test("omits custom tools from available tools section when promptSnippet is not provided", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: ["read", "dynamic_tool"],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).not.toContain("dynamic_tool");
+		});
+	});
+
+	describe("prompt guidelines", () => {
+		test("appends promptGuidelines to default guidelines", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: ["read", "dynamic_tool"],
+				promptGuidelines: ["Use dynamic_tool for project summaries."],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("- Use dynamic_tool for project summaries.");
+		});
+
+		test("deduplicates and trims promptGuidelines", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: ["read", "dynamic_tool"],
+				promptGuidelines: ["Use dynamic_tool for summaries.", "  Use dynamic_tool for summaries.  ", "   "],
+				contextFiles: [],
+				skills: [],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt.match(/- Use dynamic_tool for summaries\./g)).toHaveLength(1);
+		});
+	});
+
+	describe("skills", () => {
+		test.each([
+			{ name: "default prompt", customPrompt: undefined },
+			{ name: "custom prompt", customPrompt: "Custom system prompt" },
+		])("includes skills with only bash in the $name", ({ customPrompt }) => {
+			const prompt = buildSystemPrompt({
+				customPrompt,
+				selectedTools: ["bash"],
+				contextFiles: [],
+				skills: [testSkill],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).toContain("<available_skills>");
+			expect(prompt).toContain("<name>test-skill</name>");
+			expect(prompt).toContain("Use bash to load a skill's file");
+		});
+
+		test("omits skills without read or bash", () => {
+			const prompt = buildSystemPrompt({
+				selectedTools: ["write"],
+				contextFiles: [],
+				skills: [testSkill],
+				cwd: process.cwd(),
+			});
+
+			expect(prompt).not.toContain("<available_skills>");
+		});
+	});
+});