feat(core,cloudflare): Enable certain fields with env variables

packages/cloudflare/src/handler.ts

@@ -38,7 +38,7 @@ export function withSentry<
     QueueHandlerMessage,
     CfHostMetadata
   >,
->(optionsCallback: (env: Env) => CloudflareOptions, handler: T): T {
+>(optionsCallback: (env: Env) => CloudflareOptions | undefined, handler: T): T {
   setAsyncLocalStorageAsyncContextStrategy();
 
   try {

packages/cloudflare/src/options.ts

@@ -17,6 +17,10 @@ function isVersionMetadata(value: unknown): value is CfVersionMetadata {
   return typeof value === 'object' && value !== null && 'id' in value && typeof value.id === 'string';
 }
 
+function getEnvVar<T extends Record<string, unknown>>(env: unknown, varName: keyof T): string | undefined {
+  return typeof env === 'object' && env !== null && varName in env && typeof (env as T)[varName] === 'string' ? (env as T)[varName] as string : undefined;
+}
+
 /**
  * Merges the options passed in from the user with the options we read from
  * the Cloudflare `env` environment variable object.
@@ -31,7 +35,7 @@ function isVersionMetadata(value: unknown): value is CfVersionMetadata {
  *
  * @returns The final options.
  */
-export function getFinalOptions(userOptions: CloudflareOptions, env: unknown): CloudflareOptions {
+export function getFinalOptions(userOptions: CloudflareOptions = {}, env: unknown): CloudflareOptions {
   if (typeof env !== 'object' || env === null) {
     return userOptions;
   }
@@ -44,5 +48,13 @@ export function getFinalOptions(userOptions: CloudflareOptions, env: unknown): C
         ? env.CF_VERSION_METADATA.id
         : undefined;
 
-  return { release, ...userOptions };
+  const tracesSampleRate = userOptions.tracesSampleRate ?? parseFloat(getEnvVar(env, 'SENTRY_TRACE_SAMPLE_RATE') ?? '');
+
+  return {
+    dsn: userOptions.dsn ?? getEnvVar(env, 'SENTRY_DSN'),
+    environment: userOptions.environment ?? getEnvVar(env, 'SENTRY_ENVIRONMENT'),
+    tracesSampleRate: isFinite(tracesSampleRate) ? tracesSampleRate : undefined,
+    release,
+    ...userOptions,
+  };
 }

packages/cloudflare/test/options.test.ts

@@ -56,6 +56,60 @@ describe('getFinalOptions', () => {
     expect(result).toEqual(userOptions);
   });
 
+  it('uses SENTRY_DSN from env when user dsn is undefined', () => {
+    const userOptions = { release: 'user-release' };
+    const env = { SENTRY_DSN: 'https://key@ingest.sentry.io/1' };
+
+    const result = getFinalOptions(userOptions, env);
+
+    expect(result.dsn).toBe('https://key@ingest.sentry.io/1');
+    expect(result.release).toBe('user-release');
+  });
+
+  it('uses SENTRY_ENVIRONMENT from env when user environment is undefined', () => {
+    const userOptions = { dsn: 'test-dsn' };
+    const env = { SENTRY_ENVIRONMENT: 'staging' };
+
+    const result = getFinalOptions(userOptions, env);
+
+    expect(result.environment).toBe('staging');
+  });
+
+  it('uses SENTRY_TRACES_SAMPLE_RATE from env when user tracesSampleRate is undefined', () => {
+    const userOptions = { dsn: 'test-dsn' };
+    const env = { SENTRY_TRACES_SAMPLE_RATE: '0.5' };
+
+    const result = getFinalOptions(userOptions, env);
+
+    expect(result.tracesSampleRate).toBe(0.5);
+  });
+
+  it('does not use SENTRY_TRACES_SAMPLE_RATE from env when it is gibberish', () => {
+    const env = { SENTRY_TRACES_SAMPLE_RATE: 'ʕっ•ᴥ•ʔっ' };
+
+    const result = getFinalOptions(undefined, env);
+
+    expect(result.tracesSampleRate).toBeUndefined();
+  });
+
+  it('prefers user dsn over env SENTRY_DSN', () => {
+    const userOptions = { dsn: 'user-dsn', release: 'user-release' };
+    const env = { SENTRY_DSN: 'https://env@ingest.sentry.io/1' };
+
+    const result = getFinalOptions(userOptions, env);
+
+    expect(result.dsn).toBe('user-dsn');
+  });
+
+  it('ignores SENTRY_DSN when not a string', () => {
+    const userOptions = { dsn: undefined };
+    const env = { SENTRY_DSN: 123 };
+
+    const result = getFinalOptions(userOptions, env);
+
+    expect(result.dsn).toBeUndefined();
+  });
+
   describe('CF_VERSION_METADATA', () => {
     it('uses CF_VERSION_METADATA.id as release when no other release is set', () => {
       const userOptions = { dsn: 'test-dsn' };