Remove stackStartFunction from AssertionError

At best it saves one stack level, but AVA code is already filtered out
of the stacks, so this is really quite unnecessary.

lib/assert.js

@@ -26,8 +26,6 @@ class AssertionError extends Error {
 
 		if (opts.stack) {
 			this.stack = opts.stack;
-		} else {
-			Error.captureStackTrace(this, opts.stackStartFunction);
 		}
 	}
 }
@@ -52,8 +50,7 @@ function wrapAssertions(callbacks) {
 		fail(message) {
 			fail(this, new AssertionError({
 				assertion: 'fail',
-				message: message || 'Test failed via t.fail()',
-				stackStartFunction: assertions.fail
+				message: message || 'Test failed via t.fail()'
 			}));
 		},
 
@@ -66,8 +63,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'is',
 					expected,
 					message,
-					operator: '===',
-					stackStartFunction: assertions.is
+					operator: '==='
 				}));
 			}
 		},
@@ -79,8 +75,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'not',
 					expected,
 					message,
-					operator: '!==',
-					stackStartFunction: assertions.not
+					operator: '!=='
 				}));
 			} else {
 				pass(this);
@@ -95,8 +90,7 @@ function wrapAssertions(callbacks) {
 					actual,
 					assertion: 'deepEqual',
 					expected,
-					message,
-					stackStartFunction: assertions.deepEqual
+					message
 				}));
 			}
 		},
@@ -107,8 +101,7 @@ function wrapAssertions(callbacks) {
 					actual,
 					assertion: 'notDeepEqual',
 					expected,
-					message,
-					stackStartFunction: assertions.notDeepEqual
+					message
 				}));
 			} else {
 				pass(this);
@@ -153,8 +146,7 @@ function wrapAssertions(callbacks) {
 				} catch (err) {
 					throw new AssertionError({
 						assertion: 'throws',
-						message,
-						stackStartFunction: assertions.throws
+						message
 					});
 				}
 			};
@@ -195,8 +187,7 @@ function wrapAssertions(callbacks) {
 					throw new AssertionError({
 						actual: err.actual,
 						assertion: 'notThrows',
-						message,
-						stackStartFunction: assertions.notThrows
+						message
 					});
 				}
 			};
@@ -223,8 +214,7 @@ function wrapAssertions(callbacks) {
 				fail(this, new AssertionError({
 					actual,
 					assertion: 'ifError',
-					message,
-					stackStartFunction: assertions.ifError
+					message
 				}));
 			} else {
 				pass(this);
@@ -240,8 +230,7 @@ function wrapAssertions(callbacks) {
 					actual,
 					assertion: 'snapshot',
 					expected: result.expected,
-					message: result.message,
-					stackStartFunction: assertions.snapshot
+					message: result.message
 				}));
 			}
 		}
@@ -255,8 +244,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'truthy',
 					expected: true,
 					message,
-					operator: '==',
-					stackStartFunction: enhancedAssertions.truthy
+					operator: '=='
 				});
 			}
 		},
@@ -268,8 +256,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'falsy',
 					expected: false,
 					message,
-					operator: '==',
-					stackStartFunction: enhancedAssertions.falsy
+					operator: '=='
 				});
 			}
 		},
@@ -281,8 +268,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'true',
 					expected: true,
 					message,
-					operator: '===',
-					stackStartFunction: enhancedAssertions.true
+					operator: '==='
 				});
 			}
 		},
@@ -294,8 +280,7 @@ function wrapAssertions(callbacks) {
 					assertion: 'false',
 					expected: false,
 					message,
-					operator: '===',
-					stackStartFunction: enhancedAssertions.false
+					operator: '==='
 				});
 			}
 		},
@@ -306,8 +291,7 @@ function wrapAssertions(callbacks) {
 					actual,
 					assertion: 'regex',
 					expected,
-					message,
-					stackStartFunction: enhancedAssertions.regex
+					message
 				});
 			}
 		},
@@ -318,8 +302,7 @@ function wrapAssertions(callbacks) {
 					actual,
 					assertion: 'notRegex',
 					expected,
-					message,
-					stackStartFunction: enhancedAssertions.notRegex
+					message
 				});
 			}
 		}

lib/test.js

@@ -18,21 +18,27 @@ class SkipApi {
 	}
 }
 
+const captureStack = start => {
+	const limitBefore = Error.stackTraceLimit;
+	Error.stackTraceLimit = 1;
+	const obj = {};
+	Error.captureStackTrace(obj, start);
+	Error.stackTraceLimit = limitBefore;
+	return obj.stack;
+};
+
 class ExecutionContext {
 	constructor(test) {
 		this._test = test;
 		this.skip = new SkipApi(test);
 	}
 	plan(ct) {
-		const limitBefore = Error.stackTraceLimit;
-		Error.stackTraceLimit = 1;
-		const obj = {};
-		Error.captureStackTrace(obj, this.plan);
-		Error.stackTraceLimit = limitBefore;
-		this._test.plan(ct, obj.stack);
+		this._test.plan(ct, captureStack(this.plan));
 	}
 	get end() {
-		return this._test.end;
+		const end = this._test.end;
+		const endFn = err => end(err, captureStack(endFn));
+		return endFn;
 	}
 	get title() {
 		return this._test.title;
@@ -261,12 +267,13 @@ class Test {
 
 		throw new Error('t.end is not supported in this context. To use t.end as a callback, you must use "callback mode" via `test.cb(testName, fn)`');
 	}
-	_end(err) {
+	_end(err, stack) {
 		if (err) {
 			if (!(err instanceof assert.AssertionError)) {
 				err = new assert.AssertionError({
 					actual: err,
-					message: 'Callback called with an error'
+					message: 'Callback called with an error',
+					stack
 				});
 			}
 

test/serialize-error.js

@@ -154,6 +154,7 @@ test('serialize statements of assertion errors', t => {
 
 test('serialize actual and expected props of assertion errors', t => {
 	const err = new avaAssert.AssertionError({
+		stackStartFunction: null,
 		assertion: 'is',
 		actual: 1,
 		expected: 'a'
@@ -168,7 +169,7 @@ test('serialize actual and expected props of assertion errors', t => {
 });
 
 test('only serialize actual and expected props of assertion errors if error was created with one', t => {
-	const err = new avaAssert.AssertionError({});
+	const err = new avaAssert.AssertionError({stackStartFunction: null});
 
 	const serializedErr = serialize(err);
 	t.is(serializedErr.actual, undefined);