feat: negation support (#4)

* feat: negation support

* test: coverage for not, update old coverage

src/context.ts

@@ -6,7 +6,6 @@ function getContext(): IContext {
 	if (!runnerContext) {
 		runnerContext = {
 			collectedTests: new Map<TestFilePath, any>(),
-			collecting: true,
 		}
 	}
 

src/expect.ts

@@ -7,21 +7,36 @@ class TestAssertionFailed extends Error {
 	}
 }
 
-// TODO(mcat): This should just be using `assert`
 class Expectation<ValueType> {
 	value: ValueType
+	negated: boolean
 
 	constructor(value: ValueType) {
 		this.value = value
+		this.negated = false
+	}
+
+	/*
+	 * Negates the expectation.
+	 */
+	get not() {
+		this.negated = !this.negated
+		return this
 	}
 
 	toEqual(value: ValueType) {
-		assert.deepEqual(this.value, value, new TestAssertionFailed(`NotEqual! ${this.value} != ${value}`))
+		if (this.negated) {
+			assert.notDeepEqual(this.value, value, new TestAssertionFailed(`Equal! ${this.value} = ${value}`))
+		} else {
+			assert.deepEqual(this.value, value, new TestAssertionFailed(`NotEqual! ${this.value} != ${value}`))
+		}
 	}
 
 	toBe(value: ValueType) {
-		if (Object.is(this.value, value)) return
-		throw new TestAssertionFailed(`NotEqual! ${this.value} !== ${value}`)
+		const isSame = Object.is(this.value, value)
+
+		if ((isSame && !this.negated) || (!isSame && this.negated)) return
+		throw new TestAssertionFailed(`NotEqual! ${this.value} ${this.negated ? '===' : '!=='} ${value}`)
 	}
 }
 

src/types.ts

@@ -4,5 +4,4 @@ export type TestCaseFunction = () => void
 
 export interface IContext {
 	collectedTests: Map<TestFilePath, any>
-	collecting: boolean
 }

tests/expect.test.ts

@@ -1,73 +1,66 @@
+import assert from 'assert'
 import { test, expect } from '../src/testCaseUtils'
 
 test('Equality (number)', () => {
-	expect(1).toEqual(1)
+	assert.doesNotThrow(() => expect(1).toEqual(1))
 })
 
 test('Equality (string)', () => {
-	expect('expectations').toEqual('expectations')
+	assert.doesNotThrow(() => expect('expectations').toEqual('expectations'))
 })
 
 test('Equality (boolean)', () => {
-	expect(true).toEqual(true)
+	assert.doesNotThrow(() => expect(true).toEqual(true))
 })
 
 test('Equality (failed - number)', () => {
-	try {
-		expect(1).toEqual(2)
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect(1).toEqual(2))
 })
 
 test('Equality (failed - string)', () => {
-	try {
-		expect('expectation').toEqual('something else')
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect('expectation').toEqual('something else'))
 })
 
 test('Equality (failed - boolean)', () => {
-	try {
-		expect(true).toEqual(false)
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect(true).toEqual(false))
 })
 
 test('Identity comparison (number)', () => {
-	expect(1).toBe(1)
+	assert.doesNotThrow(() => expect(1).toBe(1))
 })
 
 test('Identity comparison (boolean)', () => {
-	expect(true).toBe(true)
+	assert.doesNotThrow(() => expect(true).toBe(true))
 })
 
 test('Identity comparison (string)', () => {
-	expect('identity').toBe('identity')
+	assert.doesNotThrow(() => expect('identity').toBe('identity'))
 })
 
 test('Identity comparison (failed - number)', () => {
-	try {
-		expect(1).toEqual(2)
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect(1).toEqual(2))
 })
 
 test('Identity comparison (failed - boolean)', () => {
-	try {
-		expect(false).toBe(true)
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect(false).toBe(true))
 })
 
 test('Identity comparison (failed - string)', () => {
-	try {
-		expect('yes').toBe('no')
-	} catch (e) {
-		expect(1).toEqual(1)
-	}
+	assert.throws(() => expect('yes').toBe('no'))
+})
+
+test('Equality negation', () => {
+	assert.doesNotThrow(() => expect('yes').not.toEqual('no'))
+})
+
+test('Stacked equality negation', () => {
+	assert.doesNotThrow(() => expect('yes').not.not.toEqual('yes'))
+})
+
+test('Identity negation', () => {
+	assert.doesNotThrow(() => expect('yes').not.toBe('no'))
+})
+
+test('Identity negation (fail)', () => {
+	assert.throws(() => expect('yes').not.toBe('yes'))
 })