Fix ReferenceError: process is not defined in native browser ESM

packages/motion-utils/src/__tests__/errors.test.ts

@@ -0,0 +1,88 @@
+import { warning, invariant } from "../errors"
+
+describe("errors", () => {
+    describe("warning", () => {
+        it("should log warning when check is false", () => {
+            const consoleSpy = jest
+                .spyOn(console, "warn")
+                .mockImplementation(() => {})
+
+            warning(false, "Test warning message")
+
+            // In non-production, warning should be called
+            if (process.env.NODE_ENV !== "production") {
+                expect(consoleSpy).toHaveBeenCalledWith(
+                    expect.stringContaining("Test warning message")
+                )
+            }
+
+            consoleSpy.mockRestore()
+        })
+
+        it("should not log warning when check is true", () => {
+            const consoleSpy = jest
+                .spyOn(console, "warn")
+                .mockImplementation(() => {})
+
+            warning(true, "Test warning message")
+
+            expect(consoleSpy).not.toHaveBeenCalled()
+
+            consoleSpy.mockRestore()
+        })
+
+        it("should include error code link in warning message", () => {
+            const consoleSpy = jest
+                .spyOn(console, "warn")
+                .mockImplementation(() => {})
+
+            warning(false, "Test message", "test-error")
+
+            if (process.env.NODE_ENV !== "production") {
+                expect(consoleSpy).toHaveBeenCalledWith(
+                    expect.stringContaining("motion.dev/troubleshooting/test-error")
+                )
+            }
+
+            consoleSpy.mockRestore()
+        })
+    })
+
+    describe("invariant", () => {
+        it("should throw error when check is false", () => {
+            if (process.env.NODE_ENV !== "production") {
+                expect(() => {
+                    invariant(false, "Test invariant message")
+                }).toThrow("Test invariant message")
+            }
+        })
+
+        it("should not throw error when check is true", () => {
+            expect(() => {
+                invariant(true, "Test invariant message")
+            }).not.toThrow()
+        })
+
+        it("should include error code link in error message", () => {
+            if (process.env.NODE_ENV !== "production") {
+                expect(() => {
+                    invariant(false, "Test message", "test-error")
+                }).toThrow(/motion\.dev\/troubleshooting\/test-error/)
+            }
+        })
+    })
+
+    describe("process guard", () => {
+        it("should handle undefined process gracefully", () => {
+            // This test verifies the fix for issue #3417
+            // The module-level code guards against process being undefined
+            // by checking `typeof process !== "undefined"` before accessing
+            // process.env.NODE_ENV
+            //
+            // We can't directly test module initialization, but we can verify
+            // that the exports are functions (meaning the module loaded successfully)
+            expect(typeof warning).toBe("function")
+            expect(typeof invariant).toBe("function")
+        })
+    })
+})

packages/motion-utils/src/errors.ts

@@ -9,7 +9,10 @@ export type DevMessage = (
 let warning: DevMessage = () => {}
 let invariant: DevMessage = () => {}
 
-if (process.env.NODE_ENV !== "production") {
+if (
+    typeof process !== "undefined" &&
+    process.env?.NODE_ENV !== "production"
+) {
     warning = (check, message, errorCode) => {
         if (!check && typeof console !== "undefined") {
             console.warn(formatErrorMessage(message, errorCode))