refactor(testing): align additional error messages

testing/_test_suite.ts

@@ -84,7 +84,9 @@ export class TestSuiteInternal<T> implements TestSuite<T> {
 
     const { suite } = describe;
     if (suite && !TestSuiteInternal.suites.has(suite.symbol)) {
-      throw new Error("suite does not represent a registered test suite");
+      throw new Error(
+        "Cannot construct Test Suite: suite does not represent a registered test suite",
+      );
     }
     const testSuite = suite
       ? TestSuiteInternal.suites.get(suite.symbol)
@@ -101,7 +103,7 @@ export class TestSuiteInternal<T> implements TestSuite<T> {
         const value = fn() as any;
         if (value instanceof Promise) {
           throw new Error(
-            'Returning a Promise from "describe" is not supported. Tests must be defined synchronously.',
+            'Returning a Promise from "describe" is not supported: tests must be defined synchronously',
           );
         }
       } finally {

testing/bdd.ts

@@ -562,7 +562,7 @@
 export function it<T>(...args: ItArgs<T>) {
   if (TestSuiteInternal.runningCount > 0) {
     throw new Error(
-      "cannot register new test cases after already registered test cases start running",
+      "Cannot register new test cases after already registered test cases start running",
     );
   }
   const options = itDefinition(...args);
@@ -717,7 +717,7 @@
   if (!TestSuiteInternal.current) {
     if (TestSuiteInternal.started) {
       throw new Error(
-        "cannot add global hooks after a global test is registered",
+        "Cannot add global hooks after a global test is registered",
       );
     }
     TestSuiteInternal.current = new TestSuiteInternal({
@@ -1070,7 +1070,7 @@
 ): TestSuite<T> {
   if (TestSuiteInternal.runningCount > 0) {
     throw new Error(
-      "cannot register new test suites after already registered test cases start running",
+      "Cannot register new test suites after already registered test cases start running",
     );
   }
   const options = describeDefinition(...args);

testing/bdd_test.ts

@@ -2055,7 +2055,7 @@ Deno.test("describe()", async (t) => {
         // deno-lint-ignore no-explicit-any
         () => describe("async describe", (async () => {}) as any),
         Error,
-        'Returning a Promise from "describe" is not supported. Tests must be defined synchronously.',
+        'Returning a Promise from "describe" is not supported: tests must be defined synchronously',
       );
     },
   );

testing/mock.ts

@@ -435,7 +435,9 @@ function functionSpy<
     restore: {
       enumerable: true,
       value: () => {
-        throw new MockError("Function cannot be restored");
+        throw new MockError(
+          "Cannot restore: function cannot be restored",
+        );
       },
     },
   });
@@ -643,15 +645,21 @@ function methodSpy<
   Return,
 >(self: Self, property: keyof Self): MethodSpy<Self, Args, Return> {
   if (typeof self[property] !== "function") {
-    throw new MockError("Property is not an instance method");
+    throw new MockError(
+      "Cannot spy: property is not an instance method",
+    );
   }
   if (isSpy(self[property])) {
-    throw new MockError("Already spying on instance method");
+    throw new MockError(
+      "Cannot spy: already spying on instance method",
+    );
   }
 
   const propertyDescriptor = Object.getOwnPropertyDescriptor(self, property);
   if (propertyDescriptor && !propertyDescriptor.configurable) {
-    throw new MockError("Cannot spy on non-configurable instance method");
+    throw new MockError(
+      "Cannot spy: non-configurable instance method",
+    );
   }
 
   const original = self[property] as unknown as (
@@ -690,7 +698,9 @@ function methodSpy<
       enumerable: true,
       value: () => {
         if (restored) {
-          throw new MockError("Instance method already restored");
+          throw new MockError(
+            "Cannot restore: instance method already restored",
+          );
         }
         if (propertyDescriptor) {
           Object.defineProperty(self, property, propertyDescriptor);
@@ -767,7 +777,9 @@ function constructorSpy<
     static readonly calls = calls;
     static readonly restored = false;
     static restore() {
-      throw new MockError("Constructor cannot be restored");
+      throw new MockError(
+        "Cannot restore: constructor cannot be restored",
+      );
     }
   } as ConstructorSpy<Self, Args>;
   return spy;
@@ -1082,15 +1094,19 @@ export function stub<
   func?: (this: Self, ...args: Args) => Return,
 ): Stub<Self, Args, Return> {
   if (self[property] !== undefined && typeof self[property] !== "function") {
-    throw new MockError("Property is not an instance method");
+    throw new MockError(
+      "Cannot stub: property is not an instance method",
+    );
   }
   if (isSpy(self[property])) {
-    throw new MockError("Already spying on instance method");
+    throw new MockError(
+      "Cannot stub: already spying on instance method",
+    );
   }
 
   const propertyDescriptor = Object.getOwnPropertyDescriptor(self, property);
   if (propertyDescriptor && !propertyDescriptor.configurable) {
-    throw new MockError("Cannot stub non-configurable instance method");
+    throw new MockError("Cannot stub: non-configurable instance method");
   }
 
   const fake = func ?? (() => {}) as (this: Self, ...args: Args) => Return;
@@ -1135,7 +1151,9 @@ export function stub<
       enumerable: true,
       value: () => {
         if (restored) {
-          throw new MockError("Instance method already restored");
+          throw new MockError(
+            "Cannot restore: instance method already restored",
+          );
         }
         if (propertyDescriptor) {
           Object.defineProperty(self, property, propertyDescriptor);

testing/mock_test.ts

@@ -79,7 +79,7 @@ Deno.test("spy()", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Function cannot be restore",
+    "Cannot restore: function cannot be restored",
   );
   assertEquals(func.restored, false);
 });
@@ -125,7 +125,7 @@ Deno.test("spy() works on function", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Function cannot be restored",
+    "Cannot restore: function cannot be restored",
   );
   assertEquals(func.restored, false);
 
@@ -239,7 +239,7 @@ Deno.test("spy() works on instance method", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(func.restored, true);
 });
@@ -277,7 +277,7 @@ Deno.test("spy() works on instance method symbol", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(func.restored, true);
 });
@@ -342,7 +342,7 @@ Deno.test("spy() works on instance method property descriptor", () => {
   assertThrows(
     () => action.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(action.restored, true);
 });
@@ -444,7 +444,7 @@ Deno.test("spy() supports explicit resource management", () => {
         if (funcRef) funcRef.restore();
       },
       MockError,
-      "Instance method already restored",
+      "Cannot restore: instance method already restored",
     );
     assertEquals(funcRef.restored, true);
   }
@@ -478,7 +478,7 @@ Deno.test("spy() works on constructor", () => {
   assertThrows(
     () => PointSpy.restore(),
     MockError,
-    "Constructor cannot be restored",
+    "Cannot restore: constructor cannot be restored",
   );
 });
 
@@ -546,7 +546,7 @@ Deno.test("spy() throws when try spying already spied method", () => {
   assertThrows(
     () => spy(obj, "fn"),
     MockError,
-    "Already spying on instance method",
+    "Cannot spy: already spying on instance method",
   );
 });
 
@@ -556,7 +556,7 @@ Deno.test("spy() throws when the property is not a method", () => {
     // deno-lint-ignore no-explicit-any
     () => spy(obj as any, "fn"),
     MockError,
-    "Property is not an instance method",
+    "Cannot spy: property is not an instance method",
   );
 });
 
@@ -566,7 +566,7 @@ Deno.test("spy() throws when the property is not configurable", () => {
   assertThrows(
     () => spy(obj, "fn"),
     MockError,
-    "Cannot spy on non-configurable instance method",
+    "Cannot spy: non-configurable instance method",
   );
 });
 
@@ -602,7 +602,7 @@ Deno.test("stub()", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(func.restored, true);
 });
@@ -640,7 +640,7 @@ Deno.test("stub() works on function", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(func.restored, true);
 });
@@ -684,7 +684,7 @@ Deno.test("stub() supports explicit resource management", () => {
         if (funcRef) funcRef.restore();
       },
       MockError,
-      "Instance method already restored",
+      "Cannot restore: instance method already restored",
     );
     assertEquals(funcRef.restored, true);
   }
@@ -727,7 +727,7 @@ Deno.test("stub() handles non existent function", () => {
   assertThrows(
     () => func.restore(),
     MockError,
-    "Instance method already restored",
+    "Cannot restore: instance method already restored",
   );
   assertEquals(func.restored, true);
 });
@@ -797,7 +797,7 @@ Deno.test("stub() throws when the property is not a method", () => {
     // deno-lint-ignore no-explicit-any
     () => stub(obj as any, "fn"),
     MockError,
-    "Property is not an instance method",
+    "Cannot stub: property is not an instance method",
   );
 });
 
@@ -807,7 +807,7 @@ Deno.test("stub() throws when try stubbing already stubbed method", () => {
   assertThrows(
     () => stub(obj, "fn"),
     MockError,
-    "Already spying on instance method",
+    "Cannot stub: already spying on instance method",
   );
 });
 
@@ -817,7 +817,7 @@ Deno.test("stub() throws then the property is not configurable", () => {
   assertThrows(
     () => stub(obj, "fn"),
     MockError,
-    "Cannot stub non-configurable instance method",
+    "Cannot stub: non-configurable instance method",
   );
 });