refactor(env): warn when using non-conventional NODE_ENV values (#2…

…7111)

# Why

Fixes ENG-9686

# How

Instead of erroring, we now warn when using a non-conventional
`NODE_ENV` value.

# Test Plan

See added tests.

- `NODE_ENV=yolo expod start` should warn

# Checklist

<!--
Please check the appropriate items below if they apply to your diff.
This is required for changes to Expo modules.
-->

- [ ] Documentation is up to date to reflect these changes (eg:
https://docs.expo.dev and README.md).
- [ ] Conforms with the [Documentation Writing Style
Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md)
- [ ] This diff will work correctly for `npx expo prebuild` & EAS Build
(eg: updated a module plugin).

packages/@expo/env/CHANGELOG.md

@@ -10,6 +10,8 @@
 
 ### 💡 Others
 
+- Warn instead of error when `NODE_ENV` is set to non-conventional value. ([#27111](https://github.com/expo/expo/pull/27111) by [@byCedric](https://github.com/byCedric))
+
 ## 0.2.1 — 2023-12-15
 
 _This version does not introduce any user-facing changes._

packages/@expo/env/src/__tests__/env.test.ts

@@ -67,10 +67,26 @@ describe(getFiles, () => {
       expect.stringContaining('Proceeding without mode-specific .env')
     );
   });
-  it(`throws if NODE_ENV is not valid`, () => {
-    expect(() => getFiles('invalid')).toThrowErrorMatchingInlineSnapshot(
-      `"Environment variable "NODE_ENV=invalid" is invalid. Valid values are "development", "test", and "production"`
+  it(`warns if NODE_ENV is not valid`, () => {
+    const warnSpy = jest.spyOn(console, 'warn');
+
+    expect(() => getFiles('invalid')).not.toThrow();
+    expect(warnSpy).toBeCalledWith(
+      expect.stringContaining('"NODE_ENV=invalid" is non-conventional')
+    );
+    expect(warnSpy).toBeCalledWith(
+      expect.stringContaining('Use "development", "test", or "production"')
     );
+
+    warnSpy.mockClear();
+  });
+  it(`does not warn if NODE_ENV is not valid when in silent mode`, () => {
+    const warnSpy = jest.spyOn(console, 'warn');
+
+    expect(() => getFiles('invalid', { silent: true })).not.toThrow();
+    expect(warnSpy).not.toBeCalled();
+
+    warnSpy.mockClear();
   });
 });
 

packages/@expo/env/src/env.ts

@@ -198,9 +198,17 @@ export function getFiles(
   }
 
   if (mode && !['development', 'test', 'production'].includes(mode)) {
-    throw new Error(
-      `Environment variable "NODE_ENV=${mode}" is invalid. Valid values are "development", "test", and "production`
-    );
+    if (silent) {
+      debug(
+        `NODE_ENV="${mode}" is non-conventional and might cause development code to run in production. Use "development", "test", or "production" instead.`
+      );
+    } else {
+      console.warn(
+        chalk.yellow(
+          `"NODE_ENV=${mode}" is non-conventional and might cause development code to run in production. Use "development", "test", or "production" instead`
+        )
+      );
+    }
   }
 
   if (!mode) {