Awesome
📼 Supertape
📼 Supertape is Tape-inspired TAP
-compatible simplest high speed test runner with superpowers. It's designed to be as compatible as possible with tape while still having some key improvements, such as:
-
the ability to work with ESM Modules (take a look at mock-import for mocking and 🎩ESCover for coverage)
-
a number of built-in pretty output formatters
-
the ability to extend
-
showing colored diff when using the
t.equal()
andt.deepEqual()
assertion operators -
detailed stack traces for
async
functions -
multiple
test.only
's -
smart timeouts for long running tests 🏃♂️
-
more natural assertions:
expected, result
->result, expected
:t.equal(error.message, 'hello world', `expected error.message to be 'hello world'`);
-
ability to generate tests with ♨️Speca
📼 Supertape doesn't contain:
- assertion aliases, making the available operators far more concise;
es3 code
and lots of ponyfills;t.throws()
,t.doesNotThrow()
- use tryCatch or tryToCatch witht.equal()
instead;t.plan()
;
For a list of all built-in assertions, see Operators.
How 📼Supertape test looks like?
You can use both CommonJS and ESM, here is ESM example:
import {test} from 'supertape';
const sump = (a, b) => a + b;
test('calc: sum', (t) => {
const result = sum(1, 2);
const expected = 3;
t.equal(result, expected);
t.end();
});
Install
npm i supertape -D
Usage
Usage: supertape [options] [path]
Options
-h, --help display this help and exit
-v, --version output version information and exit
-f, --format use a specific output format - default: progress-bar/tap on CI
-r, --require require module
--no-check-scopes do not check that messages contains scope: 'scope: message'
--no-check-assertions-count do not check that assertion count is no more then 1
--no-check-duplicates do not check messages for duplicates
--no-worker disable worker thread
Environment variables
SUPERTAPE_TIMEOUT
- timeout for long running processes, defaults to3000
(3 seconds);SUPERTAPE_CHECK_DUPLICATES
- toggle check duplicates;SUPERTAPE_CHECK_SCOPES
- check that test message has a scope:scope: subject
;SUPERTAPE_CHECK_ASSERTIONS_COUNT
- check that assertion count is no more then 1;SUPERTAPE_CHECK_SKIPED
- check that skiped count equal to0
, exit with status code;SUPERTAPE_LOAD_LOOP_TIMEOUT
- timeout for load tests, defaults to5ms
, when mocha used as runner -50ms
optimal;
test('tape: error', (t) => {
t.equal(error.code, 'ENOENT');
t.end();
});
🤷 How to migrate from tape?
🐊 + 📼 = ❤️
You can convert your codebase from Tape, or Jest to 📼Supertape with help of 🐊Putout, which has built-in @putout/plugin-tape, with a lots of rules that helps to write and maintain tests of the highest possible quality.
Here is result example.
ESLint rules
eslint-plugin-putout has a couple rules for 📼Supertape:
Validation checks
To up the quality of your tests even higher, 📼Supertape has built-in checks. When test not passes validation it marked as a new failed test.
Single t.end()
t.end()
must not be used more than once. This check cannot be disabled
and has auto fixable rule 🐊remove-useless-t-end
.
❌ Example of incorrect code
test('hello: world', (t) => {
t.end();
t.end();
});
✅ Example of correct code
test('hello: world', (t) => {
t.end();
});
Check duplicates
Check for duplicates in test messages. Can be disabled with:
- passing
--no-check-duplicates
command line flag; - setting
SUPERTAPE_CHECK_DUPLICATES=0
env variable;
❌ Example of incorrect code
test('hello: world', (t) => {
t.equal(1, 1);
t.end();
});
test('hello: world', (t) => {
t.equal(2, 1);
t.end();
});
Check scopes
Check that test message are divided on groups by colons. Can be disabled with:
- passing
--no-check-scopes
command line flag; - setting
SUPERTAPE_CHECK_SCOPES=0
env variable;
❌ Example of incorrect code
test('hello', (t) => {
t.equal(1, 1);
t.end();
});
✅ Example of correct code
test('hello: world', (t) => {
t.equal(1, 1);
t.end();
});
Check assertions count
Check that test contains exactly one assertion. Can be disabled with:
- passing
--no-check-assertions-count
command line flag; - setting
SUPERTAPE_CHECK_ASSERTIONS_COUNT=0
env variable;
❌ Example of incorrect code
test('hello: no assertion', (t) => {
t.end();
});
test('hello: more then one assertion', (t) => {
t.equal(1, 1);
t.equal(2, 2);
t.end();
});
✅ Example of correct code
test('hello: one', (t) => {
t.equal(1, 1);
t.end();
});
test('hello: two', (t) => {
t.equal(2, 2);
t.end();
});
Operators
The assertion methods of 📼 Supertape are heavily influenced by tape. However, to keep a minimal core of assertions, there are no aliases and some superfluous operators hasn't been implemented (such as t.throws()
).
The following is a list of the base methods maintained by 📼 Supertape. Others, such as assertions for stubbing, are maintained in special operators. To add custom assertion operators, see Extending.
Core Operators
t.equal(result: any, expected: any, message?: string)
Asserts that result
and expected
are strictly equal. If message
is provided, it will be outputted as a description of the assertion.
☝️ Note: uses Object.is(result, expected)
t.notEqual(result: any, expected: any, message?: string)
Asserts that result
and expected
are not strictly equal. If message
is provided, it will be outputted as a description of the assertion.
☝️ Note: uses !Object.is(result, expected)
t.deepEqual(result: any, expected: any, message?: string)
Asserts that result
and expected
are equal, with the same structure and nested values. If message
is provided, it will be outputted as a description of the assertion.
☝️ Note: uses node's isDeepStrictEqual() algorithm with strict comparisons (===
) on leaf nodes
t.notDeepEqual(result: any, expected: any, message?: string)
Asserts that result
and expected
are not equal, with different structure and/or nested values. If message
is provided, it will be outputted as a description of the assertion.
☝️ Note: uses node's isDeepStrictEqual() algorithm with strict comparisons (===
) on leaf nodes
t.ok(result: boolean | any, message?: string)
Asserts that result
is truthy. If message
is provided, it will be outputted as a description of the assertion.
t.notOk(result: boolean | any, message?: string)
Asserts that result
is falsy. If message
is provided, it will be outputted as a description of the assertion.
t.pass(message: string)
Generates a passing assertion with message
as a description.
t.fail(message: string)
Generates a failing assertion with message
as a description.
t.end()
Declares the end of a test explicitly. Must be called exactly once per test. (See: Single Call to t.end()
t.match(result: string, pattern: string | RegExp, message?: string)
Asserts that result
matches the regex pattern
. If pattern
is not a valid regex, the assertion fails. If message
is provided, it will be outputted as a description of the assertion.
t.notMatch(result: string, pattern: string | RegExp, message?: string)
Asserts that result
does not match the regex pattern
. If pattern
is not a valid regex, the assertion always fails. If message
is provided, it will be outputted as a description of the assertion.
t.comment(message: string)
Print a message without breaking the TAP
output. Useful when using a tap
-reporter such as tap-colorize
, where the output is buffered and console.log()
will print in incorrect order vis-a-vis TAP
output.
Special Operators
To simplify the core of 📼 Supertape, other operators are maintained in separate packages. The following is a list of all such packages:
Here is a list of built-int operators:
Package | Version |
---|---|
@supertape/operator-stub |
Formatters
There is a list of built-int formatters
to customize output:
Package | Version |
---|---|
@supertape/formatter-tap | |
@supertape/formatter-time | |
@supertape/formatter-fail | |
@supertape/formatter-short | |
@supertape/formatter-progress-bar | |
@supertape/formatter-json-lines |
API
test(message: string, fn: (t: Test) => void, options?: TestOptions)
Create a new test with message
string.
fn(t)
fires with the new test object t
once all preceding tests have
finished. Tests execute serially.
Here is Possible options
similar to Environment Variables but relates to one test:
checkDuplicates
;checkScopes
;-checkAssertionsCount
;timeout
;
test.only(message, fn, options?)
Like test(name, cb)
except if you use .only
this is the only test case
that will run for the entire process, all other test cases using tape
will
be ignored.
test.skip(message, fn, options?)
Extend base assertions with more:
const {extend} = require('supertape');
const test = extend({
transform: (operator) => (a, b, message = 'should transform') => {
const {is, output} = operator.equal(a + 1, b - 1);
return {
is,
output,
};
},
});
test('assertion', (t) => {
t.transform(1, 3);
t.end();
});
Example
const test = require('supertape');
test('lib: arguments', async (t) => {
throw Error('hello');
// will call t.fail with an error
// will call t.end
});
test('lib: diff', (t) => {
t.equal({}, {hello: 'world'}, 'should equal');
t.end();
});
// output
`
- Expected
+ Received
- Object {}
+ Object {
+ "hello": "world",
+ }
`;
License
MIT