feat: add Pi Coding Agent backend runtime, update dashboard UI

tests/property/pi-backend.property.test.ts

@@ -0,0 +1,143 @@
+import { describe, it } from "vitest";
+import fc from "fast-check";
+import { PiBackend } from "../../src/backends/pi-backend.js";
+import type { BackendAdapterConfig } from "../../src/backends/types.js";
+
+// Feature: multi-cli-backend, Property: Pi backend required flags
+// Validates Pi-specific CLI argument construction
+
+/**
+ * Arbitrary for non-empty strings that won't break CLI arg parsing.
+ */
+const nonEmptyString = fc.string({ minLength: 1, maxLength: 200 });
+
+/**
+ * Arbitrary for model strings (provider/model format).
+ */
+const modelString = fc.stringMatching(/^[a-z]{1,20}\/[a-z0-9-]{1,40}$/);
+
+function createBackend(model?: string): PiBackend {
+    const config: BackendAdapterConfig = {
+        cliPath: "pi",
+        workingDir: "/tmp",
+        queryTimeoutMs: 60000,
+        allowedTools: [],
+        maxTurns: 25,
+        model,
+    };
+    return new PiBackend(config);
+}
+
+describe("Pi backend required flags", () => {
+    it("generated args always contain -p for print mode", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend();
+                    const args = backend.buildArgs(prompt);
+
+                    return args.includes("-p");
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("generated args always contain --mode json", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend();
+                    const args = backend.buildArgs(prompt);
+
+                    const modeIndex = args.indexOf("--mode");
+                    return modeIndex !== -1 && args[modeIndex + 1] === "json";
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("generated args contain --model when a model is configured", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                modelString,
+                (prompt, model) => {
+                    const backend = createBackend(model);
+                    const args = backend.buildArgs(prompt);
+
+                    const modelIndex = args.indexOf("--model");
+                    return modelIndex !== -1 && args[modelIndex + 1] === model;
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("generated args do not contain --model when no model is configured", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend(undefined);
+                    const args = backend.buildArgs(prompt);
+
+                    return !args.includes("--model");
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("generated args contain --no-session for headless usage", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend();
+                    const args = backend.buildArgs(prompt);
+
+                    return args.includes("--no-session");
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("generated args contain --no-extensions, --no-skills, --no-themes for deterministic runs", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend();
+                    const args = backend.buildArgs(prompt);
+
+                    return (
+                        args.includes("--no-extensions") &&
+                        args.includes("--no-skills") &&
+                        args.includes("--no-themes")
+                    );
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+
+    it("prompt is always the last argument", () => {
+        fc.assert(
+            fc.property(
+                nonEmptyString,
+                (prompt) => {
+                    const backend = createBackend();
+                    const args = backend.buildArgs(prompt);
+
+                    return args[args.length - 1] === prompt;
+                },
+            ),
+            { numRuns: 100 },
+        );
+    });
+});