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Format values when AssertionErrors are created
Format statements, generate diffs and otherwise format values when AssertionErrors are created. Make labels contextual to the assertion. Always print power-assert statements in mini and verbose reporters, but after the values. Accept the duplication when the statement covers the value passed to the assertion. Detect whether `t.throws()` failed because no error was thrown, or because the thrown error did not meet expectations. Explicitly test `t.fail()` default message in assertion test.
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-704
lines changed

18 files changed

+845
-704
lines changed

‎lib/assert.js‎

Lines changed: 72 additions & 54 deletions
Original file line numberDiff line numberDiff line change
@@ -7,22 +7,20 @@ const isObservable = require('is-observable');
77
const isPromise = require('is-promise');
88
const jestSnapshot = require('jest-snapshot');
99
const enhanceAssert = require('./enhance-assert');
10+
const formatAssertError = require('./format-assert-error');
1011
const snapshotState = require('./snapshot-state');
1112

1213
class AssertionError extends Error {
1314
constructor(opts) {
1415
super(opts.message || '');
1516
this.name = 'AssertionError';
1617

17-
this.actual = opts.actual;
1818
this.assertion = opts.assertion;
19-
this.expected = opts.expected;
20-
this.hasActual = 'actual' in opts;
21-
this.hasExpected = 'expected' in opts;
2219
this.operator = opts.operator;
20+
this.values = opts.values || [];
2321

2422
// Reserved for power-assert statements
25-
this.statements = null;
23+
this.statements = [];
2624

2725
if (opts.stack) {
2826
this.stack = opts.stack;
@@ -58,24 +56,28 @@ function wrapAssertions(callbacks) {
5856
if (actual === expected) {
5957
pass(this);
6058
} else {
59+
const diff = formatAssertError.formatDiff(actual, expected);
60+
const values = diff ? [diff] : [
61+
formatAssertError.formatWithLabel('Actual:', actual),
62+
formatAssertError.formatWithLabel('Must be strictly equal to:', expected)
63+
];
64+
6165
fail(this, new AssertionError({
62-
actual,
6366
assertion: 'is',
64-
expected,
6567
message,
66-
operator: '==='
68+
operator: '===',
69+
values
6770
}));
6871
}
6972
},
7073

7174
not(actual, expected, message) {
7275
if (actual === expected) {
7376
fail(this, new AssertionError({
74-
actual,
7577
assertion: 'not',
76-
expected,
7778
message,
78-
operator: '!=='
79+
operator: '!==',
80+
values: [formatAssertError.formatWithLabel('Value is strictly equal:', actual)]
7981
}));
8082
} else {
8183
pass(this);
@@ -86,22 +88,26 @@ function wrapAssertions(callbacks) {
8688
if (deepEqual(actual, expected)) {
8789
pass(this);
8890
} else {
91+
const diff = formatAssertError.formatDiff(actual, expected);
92+
const values = diff ? [diff] : [
93+
formatAssertError.formatWithLabel('Actual:', actual),
94+
formatAssertError.formatWithLabel('Must be deeply equal to:', expected)
95+
];
96+
8997
fail(this, new AssertionError({
90-
actual,
9198
assertion: 'deepEqual',
92-
expected,
93-
message
99+
message,
100+
values
94101
}));
95102
}
96103
},
97104

98105
notDeepEqual(actual, expected, message) {
99106
if (deepEqual(actual, expected)) {
100107
fail(this, new AssertionError({
101-
actual,
102108
assertion: 'notDeepEqual',
103-
expected,
104-
message
109+
message,
110+
values: [formatAssertError.formatWithLabel('Value is deeply equal:', actual)]
105111
}));
106112
} else {
107113
pass(this);
@@ -116,8 +122,9 @@ function wrapAssertions(callbacks) {
116122
promise = observableToPromise(fn);
117123
} else if (typeof fn !== 'function') {
118124
fail(this, new AssertionError({
119-
actual: fn,
120-
message: '`t.throws()` must be called with a function, Promise, or Observable'
125+
assertion: 'throws',
126+
message: '`t.throws()` must be called with a function, Promise, or Observable',
127+
values: [formatAssertError.formatWithLabel('Called with:', fn)]
121128
}));
122129
return;
123130
}
@@ -132,21 +139,28 @@ function wrapAssertions(callbacks) {
132139
}
133140

134141
const test = fn => {
142+
let actual;
143+
let threw = false;
135144
try {
136-
let retval;
137145
coreAssert.throws(() => {
138146
try {
139147
fn();
140148
} catch (err) {
141-
retval = err;
149+
actual = err;
150+
threw = true;
142151
throw err;
143152
}
144153
}, coreAssertThrowsErrorArg);
145-
return retval;
154+
return actual;
146155
} catch (err) {
156+
const values = threw ?
157+
[formatAssertError.formatWithLabel('Threw unexpected exception:', actual)] :
158+
null;
159+
147160
throw new AssertionError({
148161
assertion: 'throws',
149-
message
162+
message,
163+
values
150164
});
151165
}
152166
};
@@ -174,8 +188,9 @@ function wrapAssertions(callbacks) {
174188
promise = observableToPromise(fn);
175189
} else if (typeof fn !== 'function') {
176190
fail(this, new AssertionError({
177-
actual: fn,
178-
message: '`t.notThrows()` must be called with a function, Promise, or Observable'
191+
assertion: 'notThrows',
192+
message: '`t.notThrows()` must be called with a function, Promise, or Observable',
193+
values: [formatAssertError.formatWithLabel('Called with:', fn)]
179194
}));
180195
return;
181196
}
@@ -185,9 +200,9 @@ function wrapAssertions(callbacks) {
185200
coreAssert.doesNotThrow(fn);
186201
} catch (err) {
187202
throw new AssertionError({
188-
actual: err.actual,
189203
assertion: 'notThrows',
190-
message
204+
message,
205+
values: [formatAssertError.formatWithLabel('Threw:', err.actual)]
191206
});
192207
}
193208
};
@@ -212,9 +227,9 @@ function wrapAssertions(callbacks) {
212227
ifError(actual, message) {
213228
if (actual) {
214229
fail(this, new AssertionError({
215-
actual,
216230
assertion: 'ifError',
217-
message
231+
message,
232+
values: [formatAssertError.formatWithLabel('Error:', actual)]
218233
}));
219234
} else {
220235
pass(this);
@@ -226,11 +241,16 @@ function wrapAssertions(callbacks) {
226241
if (result.pass) {
227242
pass(this);
228243
} else {
244+
const diff = formatAssertError.formatDiff(actual, result.expected);
245+
const values = diff ? [diff] : [
246+
formatAssertError.formatWithLabel('Actual:', actual),
247+
formatAssertError.formatWithLabel('Must be deeply equal to:', result.expected)
248+
];
249+
229250
fail(this, new AssertionError({
230-
actual,
231251
assertion: 'snapshot',
232-
expected: result.expected,
233-
message: result.message
252+
message: result.message,
253+
values
234254
}));
235255
}
236256
}
@@ -240,69 +260,67 @@ function wrapAssertions(callbacks) {
240260
truthy(actual, message) {
241261
if (!actual) {
242262
throw new AssertionError({
243-
actual,
244263
assertion: 'truthy',
245-
expected: true,
246264
message,
247-
operator: '=='
265+
operator: '!!',
266+
values: [formatAssertError.formatWithLabel('Value is not truthy:', actual)]
248267
});
249268
}
250269
},
251270

252271
falsy(actual, message) {
253272
if (actual) {
254273
throw new AssertionError({
255-
actual,
256274
assertion: 'falsy',
257-
expected: false,
258275
message,
259-
operator: '=='
276+
operator: '!',
277+
values: [formatAssertError.formatWithLabel('Value is not falsy:', actual)]
260278
});
261279
}
262280
},
263281

264282
true(actual, message) {
265283
if (actual !== true) {
266284
throw new AssertionError({
267-
actual,
268285
assertion: 'true',
269-
expected: true,
270286
message,
271-
operator: '==='
287+
values: [formatAssertError.formatWithLabel('Value is not `true`:', actual)]
272288
});
273289
}
274290
},
275291

276292
false(actual, message) {
277293
if (actual !== false) {
278294
throw new AssertionError({
279-
actual,
280295
assertion: 'false',
281-
expected: false,
282296
message,
283-
operator: '==='
297+
values: [formatAssertError.formatWithLabel('Value is not `false`:', actual)]
284298
});
285299
}
286300
},
287301

288-
regex(actual, expected, message) {
289-
if (!expected.test(actual)) {
302+
regex(string, regex, message) {
303+
if (!regex.test(string)) {
290304
throw new AssertionError({
291-
actual,
292305
assertion: 'regex',
293-
expected,
294-
message
306+
message,
307+
values: [
308+
formatAssertError.formatWithLabel('Value must match expression:', string),
309+
formatAssertError.formatWithLabel('Regular expression:', regex)
310+
]
295311
});
296312
}
297313
},
298314

299-
notRegex(actual, expected, message) {
300-
if (expected.test(actual)) {
315+
notRegex(string, regex, message) {
316+
if (regex.test(string)) {
301317
throw new AssertionError({
302-
actual,
303318
assertion: 'notRegex',
304-
expected,
305-
message
319+
message,
320+
values: [
321+
formatAssertError.formatWithLabel('Value must not match expression:', string),
322+
formatAssertError.formatWithLabel('Regular expression:', regex)
323+
]
306324
});
307325
}
308326
}

‎lib/enhance-assert.js‎

Lines changed: 5 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,6 @@
11
'use strict';
22
const dotProp = require('dot-prop');
3+
const formatValue = require('./format-assert-error');
34

45
// When adding patterns, don't forget to add to
56
// https://github.com/avajs/babel-preset-transform-test-files/blob/master/espower-patterns.json
@@ -36,7 +37,7 @@ const formatter = context => {
3637
return args
3738
.map(arg => {
3839
const range = getNode(ast, arg.espath).range;
39-
return [computeStatement(tokens, range), arg.value];
40+
return [computeStatement(tokens, range), formatValue(arg.value)];
4041
})
4142
.reverse();
4243
};
@@ -47,7 +48,9 @@ const enhanceAssert = (pass, fail, assertions) => {
4748
destructive: true,
4849
onError(event) {
4950
const error = event.error;
50-
error.statements = formatter(event.powerAssertContext);
51+
if (event.powerAssertContext) { // Context may be missing in internal tests.
52+
error.statements = formatter(event.powerAssertContext);
53+
}
5154
fail(this, error);
5255
},
5356
onSuccess() {

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