feat: auto-add $schema to config files during verification

Author: kenryu42

src/core/verify-config.ts

@@ -2,7 +2,7 @@
  * Verify user and project scope config files for safety-net.
  */
 
-import { existsSync } from "node:fs";
+import { existsSync, readFileSync, writeFileSync } from "node:fs";
 import { resolve } from "node:path";
 import {
 	getProjectConfigPath,
@@ -18,6 +18,8 @@ export interface VerifyConfigOptions {
 
 const HEADER = "Safety Net Config";
 const SEPARATOR = "═".repeat(HEADER.length);
+const SCHEMA_URL =
+	"https://raw.githubusercontent.com/kenryu42/claude-code-safety-net/main/assets/cc-safety-net.schema.json";
 
 function printHeader(): void {
 	console.log(HEADER);
@@ -58,6 +60,23 @@ function printInvalidConfig(
 	}
 }
 
+function addSchemaIfMissing(path: string): boolean {
+	try {
+		const content = readFileSync(path, "utf-8");
+		const parsed = JSON.parse(content) as Record<string, unknown>;
+
+		if (parsed.$schema) {
+			return false;
+		}
+
+		const updated = { $schema: SCHEMA_URL, ...parsed };
+		writeFileSync(path, JSON.stringify(updated, null, 2), "utf-8");
+		return true;
+	} catch {
+		return false;
+	}
+}
+
 /**
  * Verify config files and print results.
  * @returns Exit code (0 = success, 1 = errors found)
@@ -104,6 +123,9 @@ export function verifyConfig(options: VerifyConfigOptions = {}): number {
 		if (result.errors.length > 0) {
 			printInvalidConfig(scope, path, result.errors);
 		} else {
+			if (addSchemaIfMissing(path)) {
+				console.log(`\nAdded $schema to ${scope.toLowerCase()} config.`);
+			}
 			printValidConfig(scope, path, result);
 		}
 	}

tests/verify-config.test.ts

@@ -1,5 +1,11 @@
 import { afterEach, beforeEach, describe, expect, test } from "bun:test";
-import { existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import {
+	existsSync,
+	mkdirSync,
+	readFileSync,
+	rmSync,
+	writeFileSync,
+} from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import {
@@ -286,4 +292,80 @@ describe("verify-config", () => {
 			expect(stdout).toContain("✓ Project config:");
 		});
 	});
+
+	describe("schema auto-add", () => {
+		function readProjectConfig(): Record<string, unknown> {
+			return JSON.parse(readFileSync(projectConfigPath, "utf-8"));
+		}
+
+		function readUserConfig(): Record<string, unknown> {
+			return JSON.parse(readFileSync(userConfigPath, "utf-8"));
+		}
+
+		test("adds $schema to valid project config missing it", () => {
+			writeProjectConfig('{"version": 1}');
+			runMain();
+			const config = readProjectConfig();
+			expect(config.$schema).toBe(
+				"https://raw.githubusercontent.com/kenryu42/claude-code-safety-net/main/assets/cc-safety-net.schema.json",
+			);
+		});
+
+		test("adds $schema to valid user config missing it", () => {
+			writeUserConfig('{"version": 1}');
+			runMain();
+			const config = readUserConfig();
+			expect(config.$schema).toBe(
+				"https://raw.githubusercontent.com/kenryu42/claude-code-safety-net/main/assets/cc-safety-net.schema.json",
+			);
+		});
+
+		test("does not modify config that already has $schema", () => {
+			const originalConfig = {
+				$schema:
+					"https://raw.githubusercontent.com/kenryu42/claude-code-safety-net/main/assets/cc-safety-net.schema.json",
+				version: 1,
+			};
+			writeProjectConfig(JSON.stringify(originalConfig, null, 2));
+			runMain();
+			const config = readProjectConfig();
+			expect(config).toEqual(originalConfig);
+		});
+
+		test("preserves existing rules when adding $schema", () => {
+			const originalConfig = {
+				version: 1,
+				rules: [
+					{
+						name: "block-foo",
+						command: "foo",
+						block_args: ["-x"],
+						reason: "Blocked",
+					},
+				],
+			};
+			writeProjectConfig(JSON.stringify(originalConfig));
+			runMain();
+			const config = readProjectConfig();
+			expect(config.$schema).toBe(
+				"https://raw.githubusercontent.com/kenryu42/claude-code-safety-net/main/assets/cc-safety-net.schema.json",
+			);
+			expect(config.version).toBe(1);
+			expect(config.rules).toEqual(originalConfig.rules);
+		});
+
+		test("does not add $schema to invalid config", () => {
+			writeProjectConfig('{"version": 2}');
+			runMain();
+			const config = readProjectConfig();
+			expect(config.$schema).toBeUndefined();
+		});
+
+		test("prints message when $schema is added", () => {
+			writeProjectConfig('{"version": 1}');
+			runMain();
+			const output = getStdout();
+			expect(output).toContain("Added $schema");
+		});
+	});
 });