feat: add persona binding algorithm

packages/core/src/config.test.ts

@@ -1,9 +1,10 @@
-import { mkdirSync, mkdtempSync, realpathSync, writeFileSync } from "node:fs";
+import { chmodSync, mkdirSync, mkdtempSync, realpathSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
 
 import { loadConfigFromSources } from "./config.js";
+import { DevflowError } from "./errors.js";
 
 describe("config loader", () => {
   it("loads .env, .env.local, then process env in descending precedence", () => {
@@ -49,7 +50,100 @@ describe("config loader", () => {
     expect(config.backends).toContainEqual({ id: "fake", enabled: true });
   });
 
-  it("parses backend registration from DEVFLOW_BACKENDS_JSON", () => {
+  it("resolves backend binaries from PATH during config load", () => {
+    const root = mkdtempSync(join(tmpdir(), "devflow-config-"));
+    const workspace = join(root, "workspace");
+    const binDir = join(root, "bin");
+    const codexBin = join(binDir, "codex");
+    mkdirSync(workspace);
+    mkdirSync(binDir);
+    writeFileSync(codexBin, "#!/bin/sh\nexit 0\n");
+    chmodSync(codexBin, 0o755);
+
+    const config = loadConfigFromSources({
+      cwd: root,
+      env: {
+        DATABASE_URL: "postgres://devflow:devflow@localhost:5432/devflow",
+        WORKSPACE_ROOT: workspace,
+        LOG_LEVEL: "info",
+        PATH: binDir,
+        DEVFLOW_BACKENDS_JSON: JSON.stringify([{ id: "codex", enabled: true }]),
+      },
+    });
+
+    expect(config.backends).toEqual([
+      { id: "fake", enabled: true },
+      { id: "codex", enabled: true, binaryPath: realpathSync(codexBin) },
+    ]);
+  });
+
+  it("keeps enabled real backends unavailable when their binary cannot be resolved", () => {
+    const root = mkdtempSync(join(tmpdir(), "devflow-config-"));
+    const workspace = join(root, "workspace");
+    const emptyBin = join(root, "empty-bin");
+    mkdirSync(workspace);
+    mkdirSync(emptyBin);
+
+    const config = loadConfigFromSources({
+      cwd: root,
+      env: {
+        DATABASE_URL: "postgres://devflow:devflow@localhost:5432/devflow",
+        WORKSPACE_ROOT: workspace,
+        LOG_LEVEL: "info",
+        PATH: emptyBin,
+        DEVFLOW_BACKENDS_JSON: JSON.stringify([{ id: "codex", enabled: true }]),
+      },
+    });
+
+    expect(config.backends).toEqual([
+      { id: "fake", enabled: true },
+      { id: "codex", enabled: true },
+    ]);
+  });
+
+  it("requires LOG_LEVEL and classifies invalid config as fatal", () => {
+    const root = mkdtempSync(join(tmpdir(), "devflow-config-"));
+    const workspace = join(root, "workspace");
+    mkdirSync(workspace);
+
+    let caught: unknown;
+    try {
+      loadConfigFromSources({
+        cwd: root,
+        env: {
+          DATABASE_URL: "postgres://devflow:devflow@localhost:5432/devflow",
+          WORKSPACE_ROOT: workspace,
+        },
+      });
+    } catch (error) {
+      caught = error;
+    }
+
+    expect(caught).toBeInstanceOf(DevflowError);
+    expect((caught as DevflowError).class).toBe("fatal");
+    expect((caught as DevflowError).code).toBe("config_invalid");
+    expect((caught as DevflowError).cause).toBeDefined();
+  });
+
+  it("classifies malformed backend JSON as invalid config", () => {
+    const root = mkdtempSync(join(tmpdir(), "devflow-config-"));
+    const workspace = join(root, "workspace");
+    mkdirSync(workspace);
+
+    expect(() =>
+      loadConfigFromSources({
+        cwd: root,
+        env: {
+          DATABASE_URL: "postgres://devflow:devflow@localhost:5432/devflow",
+          WORKSPACE_ROOT: workspace,
+          LOG_LEVEL: "info",
+          DEVFLOW_BACKENDS_JSON: "{",
+        },
+      }),
+    ).toThrow(DevflowError);
+  });
+
+  it("freezes config and backend registrations", () => {
     const root = mkdtempSync(join(tmpdir(), "devflow-config-"));
     const workspace = join(root, "workspace");
     mkdirSync(workspace);
@@ -60,15 +154,14 @@ describe("config loader", () => {
         DATABASE_URL: "postgres://devflow:devflow@localhost:5432/devflow",
         WORKSPACE_ROOT: workspace,
         LOG_LEVEL: "info",
-        DEVFLOW_BACKENDS_JSON: JSON.stringify([
-          { id: "codex", enabled: true, binaryPath: "/usr/local/bin/codex" },
-        ]),
       },
     });
 
-    expect(config.backends).toEqual([
-      { id: "fake", enabled: true },
-      { id: "codex", enabled: true, binaryPath: "/usr/local/bin/codex" },
-    ]);
+    expect(Object.isFrozen(config)).toBe(true);
+    expect(Object.isFrozen(config.backends)).toBe(true);
+    expect(Object.isFrozen(config.backends[0])).toBe(true);
+    expect(() => {
+      (config.backends[0] as { enabled: boolean }).enabled = false;
+    }).toThrow(TypeError);
   });
 });