fix(cli): telemetry json parse crash (#5405)

fixes `supabase start` crashing with `JSON Parse error: Unexpected EOF`
from a malformed `telemetry.json` by
recovering and regenerating unreadable telemetry state 

- closes #5395

---------

Co-authored-by: Colum Ferry <cferry09@gmail.com>

Author: 7ttp

apps/cli-e2e/src/tests/telemetry.e2e.test.ts

@@ -1,4 +1,4 @@
-import { chmodSync, writeFileSync } from "node:fs";
+import { chmodSync, readFileSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect } from "vitest";
 import { testBehaviour, testParity } from "./test-context.ts";
@@ -58,9 +58,12 @@ describe("telemetry", () => {
     });
 
     testBehaviour("handles corrupted config gracefully", async ({ run, workspace }) => {
-      writeFileSync(join(workspace.path, "telemetry.json"), "{{not valid json}}");
+      const telemetryPath = join(workspace.path, "telemetry.json");
+      writeFileSync(telemetryPath, "{{not valid json}}");
       const result = await run(["telemetry", "status"]);
-      expect(result.exitCode).not.toBe(0);
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toMatch(/Telemetry is (enabled|disabled)\./);
+      expect(() => JSON.parse(readFileSync(telemetryPath, "utf8"))).not.toThrow();
     });
 
     testParity(["telemetry", "status"]);

apps/cli/src/shared/telemetry/consent.ts

@@ -4,6 +4,14 @@ import type { ConsentState, TelemetryConfig } from "./types.ts";
 
 export const getConfigDir = CliConfig.useSync((cliConfig) => cliConfig.supabaseHome);
 
+function parseTelemetryConfig(content: string): TelemetryConfig | null {
+  try {
+    return JSON.parse(content) as TelemetryConfig;
+  } catch {
+    return null;
+  }
+}
+
 export const readTelemetryConfig = Effect.fnUntraced(
   function* (configDir: string) {
     const fs = yield* FileSystem.FileSystem;
@@ -12,7 +20,7 @@ export const readTelemetryConfig = Effect.fnUntraced(
     const exists = yield* fs.exists(configPath);
     if (!exists) return null;
     const content = yield* fs.readFileString(configPath);
-    return JSON.parse(content) as TelemetryConfig;
+    return parseTelemetryConfig(content);
   },
   (effect) => Effect.orElseSucceed(effect, () => null),
 );
@@ -24,11 +32,10 @@ export const writeTelemetryConfig = Effect.fnUntraced(function* (
   const fs = yield* FileSystem.FileSystem;
   const path = yield* Path.Path;
   yield* fs.makeDirectory(configDir, { recursive: true, mode: 0o700 });
-  yield* fs.writeFileString(
-    path.join(configDir, "telemetry.json"),
-    JSON.stringify(config, null, 2),
-    { mode: 0o600 },
-  );
+  const configPath = path.join(configDir, "telemetry.json");
+  const tmpPath = `${configPath}.tmp.${Date.now()}`;
+  yield* fs.writeFileString(tmpPath, JSON.stringify(config, null, 2), { mode: 0o600 });
+  yield* fs.rename(tmpPath, configPath);
 }, Effect.orDie);
 
 export const getEffectiveConsent = Effect.fnUntraced(function* (config: TelemetryConfig | null) {

apps/cli/src/shared/telemetry/consent.unit.test.ts

@@ -1,12 +1,16 @@
 import { describe, expect, it } from "@effect/vitest";
+import { BunServices } from "@effect/platform-bun";
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
 import { Effect, Layer } from "effect";
 import { cliConfigLayer } from "../../next/config/cli-config.layer.ts";
 import {
   mockProjectContext,
   mockRuntimeInfo,
   processEnvLayer,
 } from "../../../tests/helpers/mocks.ts";
-import { getEffectiveConsent } from "./consent.ts";
+import { getEffectiveConsent, readTelemetryConfig } from "./consent.ts";
 import type { TelemetryConfig } from "./types.ts";
 
 function makeConfig(consent: TelemetryConfig["consent"]): TelemetryConfig {
@@ -40,6 +44,14 @@ function emptyEnv() {
   );
 }
 
+function makeTempDir(): string {
+  return mkdtempSync(path.join(tmpdir(), "supabase-consent-test-"));
+}
+
+function writeTelemetryFile(dir: string, content: string): void {
+  writeFileSync(path.join(dir, "telemetry.json"), content);
+}
+
 describe("getEffectiveConsent", () => {
   it.live("returns denied when DO_NOT_TRACK=1", () =>
     Effect.gen(function* () {
@@ -90,3 +102,18 @@ describe("getEffectiveConsent", () => {
     }).pipe(Effect.provide(emptyEnv())),
   );
 });
+
+describe("readTelemetryConfig", () => {
+  it.live("returns null for malformed JSON instead of throwing", () => {
+    const dir = makeTempDir();
+    writeTelemetryFile(dir, "");
+
+    return Effect.gen(function* () {
+      const config = yield* readTelemetryConfig(dir);
+      expect(config).toBeNull();
+    }).pipe(
+      Effect.provide(BunServices.layer),
+      Effect.ensuring(Effect.sync(() => rmSync(dir, { recursive: true, force: true }))),
+    );
+  });
+});

apps/cli/src/shared/telemetry/runtime.layer.unit.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "@effect/vitest";
 import { BunServices } from "@effect/platform-bun";
-import { existsSync, mkdtempSync, rmSync } from "node:fs";
+import { existsSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import path from "node:path";
 import { Effect, Layer } from "effect";
@@ -79,4 +79,20 @@ describe("telemetryRuntimeLayer", () => {
       Effect.ensuring(Effect.sync(() => rmSync(homeDir, { recursive: true, force: true }))),
     );
   });
+
+  it.live("treats a malformed telemetry.json as a fresh first run instead of crashing", () => {
+    const homeDir = makeTempDir();
+    const configPath = path.join(homeDir, "telemetry.json");
+    writeFileSync(configPath, "");
+
+    return Effect.gen(function* () {
+      const runtime = yield* TelemetryRuntime;
+      expect(runtime.consent).toBe("granted");
+      expect(runtime.isFirstRun).toBe(true);
+      expect(existsSync(configPath)).toBe(true);
+    }).pipe(
+      Effect.provide(buildLayer({ homeDir })),
+      Effect.ensuring(Effect.sync(() => rmSync(homeDir, { recursive: true, force: true }))),
+    );
+  });
 });