golang-stretchr-testify

Name: golang-stretchr-testify
Author: samber

33kinstalls179forks

How to install golang-stretchr-testify?

samber/cc-skills-golang/golang-stretchr-testify

$npx -y skills add samber/cc-skills-golang --skill golang-stretchr-testify

Installs into the current project.

Summary

Comprehensive guide to stretchr/testify for Golang testing. Covers assert, require, mock, and suite packages in depth. Use when writing tests with testify, creating mocks, setting up test suites, or choosing between assert and require. Covers testify assertions, mock expectations

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SKILL.md

1	Persona: You are a Go engineer who treats tests as executable specifications. You write tests to constrain behavior and make failures self-explanatory — not to hit coverage targets.
2
3	Modes:
4
5	- Write mode — adding new tests or mocks to a codebase.
6	- Review mode — auditing existing test code for testify misuse.
7
8	# stretchr/testify
9
10	testify complements Go's `testing` package with readable assertions, mocks, and suites. It does not replace `testing` — always use `*testing.T` as the entry point.
11
12	This skill is not exhaustive. Please refer to library documentation and code examples for more information. For Go package docs, symbols, versions, importers, and known vulnerabilities, → See `samber/cc-skills-golang@golang-pkg-go-dev` skill (`godig`) — prefer it over Context7 for Go package facts. To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See `samber/cc-skills-golang@golang-gopls` skill (`gopls`). Context7 remains a fallback for docs not indexed on pkg.go.dev.
13
14	## assert vs require
15
16	Both offer identical assertions. The difference is failure behavior:
17
18	- assert: records failure, continues — see all failures at once
19	- require: calls `t.FailNow()` — use for preconditions where continuing would panic or mislead
20
21	Use `assert.New(t)` / `require.New(t)` for readability. Name them `is` and `must`:
22
23	```go
24	func TestParseConfig(t *testing.T) {
25	is := assert.New(t)
26	must := require.New(t)
27
28	cfg, err := ParseConfig("testdata/valid.yaml")
29	must.NoError(err) // stop if parsing fails — cfg would be nil
30	must.NotNil(cfg)
31
32	is.Equal("production", cfg.Environment)
33	is.Equal(8080, cfg.Port)
34	is.True(cfg.TLS.Enabled)
35	}
36	```
37
38	Rule: `require` for preconditions (setup, error checks), `assert` for verifications. Never mix randomly.
39
40	## Core Assertions
41
42	```go
43	is := assert.New(t)
44
45	// Equality
46	is.Equal(expected, actual) // DeepEqual + exact type
47	is.NotEqual(unexpected, actual)
48	is.EqualValues(expected, actual) // converts to common type first
49	is.EqualExportedValues(expected, actual)
50
51	// Nil / Bool / Emptiness
52	is.Nil(obj) is.NotNil(obj)
53	is.True(cond) is.False(cond)
54	is.Empty(collection) is.NotEmpty(collection)
55	is.Len(collection, n)
56
57	// Contains (strings, slices, map keys)
58	is.Contains("hello world", "world")
59	is.Contains([]int{1, 2, 3}, 2)
60	is.Contains(map[string]int{"a": 1}, "a")
61
62	// Comparison
63	is.Greater(actual, threshold) is.Less(actual, ceiling)
64	is.Positive(val) is.Negative(val)
65	is.Zero(val)
66
67	// Errors
68	is.Error(err) is.NoError(err)
69	is.ErrorIs(err, ErrNotFound) // walks error chain
70	is.ErrorAs(err, &target)
71	is.ErrorContains(err, "not found")
72
73	// Type
74	is.IsType(&User{}, obj)
75	is.Implements((*io.Reader)(nil), obj)
76	```
77
78	Argument order: always `(expected, actual)` — swapping produces confusing diff output.
79
80	## Advanced Assertions
81
82	```go
83	is.ElementsMatch([]string{"b", "a", "c"}, result) // unordered comparison
84	is.InDelta(3.14, computedPi, 0.01) // float tolerance
85	is.JSONEq(`{"name":"alice"}`, `{"name": "alice"}`) // ignores whitespace/key order
86	is.WithinDuration(expected, actual, 5*time.Second)
87	is.Regexp(`^user-[a-f0-9]+$`, userID)
88
89	// Async polling
90	is.Eventually(func() bool {
91	status, _ := client.GetJobStatus(jobID)
92	return status == "completed"
93	}, 5time.Second, 100time.Millisecond)
94
95	// Async polling with rich assertions
96	is.EventuallyWithT(func(c *assert.CollectT) {
97	resp, err := client.GetOrder(orderID)
98	assert.NoError(c, err)
99	assert.Equal(c, "shipped", resp.Status)
100	}, 10time.Second, 500time.Millisecond)
101	```
102
103	## testify/mock
104
105	Mock interfaces to isolate the unit under test. E

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golang-stretchr-testify

33kinstalls179forks

View on GitHub

How to install golang-stretchr-testify?

samber/cc-skills-golang/golang-stretchr-testify

$npx -y skills add samber/cc-skills-golang --skill golang-stretchr-testify

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	Persona: You are a Go engineer who treats tests as executable specifications. You write tests to constrain behavior and make failures self-explanatory — not to hit coverage targets.
2
3	Modes:
4
5	- Write mode — adding new tests or mocks to a codebase.
6	- Review mode — auditing existing test code for testify misuse.
7
8	# stretchr/testify
9
10	testify complements Go's `testing` package with readable assertions, mocks, and suites. It does not replace `testing` — always use `*testing.T` as the entry point.
11
12	This skill is not exhaustive. Please refer to library documentation and code examples for more information. For Go package docs, symbols, versions, importers, and known vulnerabilities, → See `samber/cc-skills-golang@golang-pkg-go-dev` skill (`godig`) — prefer it over Context7 for Go package facts. To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See `samber/cc-skills-golang@golang-gopls` skill (`gopls`). Context7 remains a fallback for docs not indexed on pkg.go.dev.
13
14	## assert vs require
15
16	Both offer identical assertions. The difference is failure behavior:
17
18	- assert: records failure, continues — see all failures at once
19	- require: calls `t.FailNow()` — use for preconditions where continuing would panic or mislead
20
21	Use `assert.New(t)` / `require.New(t)` for readability. Name them `is` and `must`:
22
23	```go
24	func TestParseConfig(t *testing.T) {
25	is := assert.New(t)
26	must := require.New(t)
27
28	cfg, err := ParseConfig("testdata/valid.yaml")
29	must.NoError(err) // stop if parsing fails — cfg would be nil
30	must.NotNil(cfg)
31
32	is.Equal("production", cfg.Environment)
33	is.Equal(8080, cfg.Port)
34	is.True(cfg.TLS.Enabled)
35	}
36	```
37
38	Rule: `require` for preconditions (setup, error checks), `assert` for verifications. Never mix randomly.
39
40	## Core Assertions
41
42	```go
43	is := assert.New(t)
44
45	// Equality
46	is.Equal(expected, actual) // DeepEqual + exact type
47	is.NotEqual(unexpected, actual)
48	is.EqualValues(expected, actual) // converts to common type first
49	is.EqualExportedValues(expected, actual)
50
51	// Nil / Bool / Emptiness
52	is.Nil(obj) is.NotNil(obj)
53	is.True(cond) is.False(cond)
54	is.Empty(collection) is.NotEmpty(collection)
55	is.Len(collection, n)
56
57	// Contains (strings, slices, map keys)
58	is.Contains("hello world", "world")
59	is.Contains([]int{1, 2, 3}, 2)
60	is.Contains(map[string]int{"a": 1}, "a")
61
62	// Comparison
63	is.Greater(actual, threshold) is.Less(actual, ceiling)
64	is.Positive(val) is.Negative(val)
65	is.Zero(val)
66
67	// Errors
68	is.Error(err) is.NoError(err)
69	is.ErrorIs(err, ErrNotFound) // walks error chain
70	is.ErrorAs(err, &target)
71	is.ErrorContains(err, "not found")
72
73	// Type
74	is.IsType(&User{}, obj)
75	is.Implements((*io.Reader)(nil), obj)
76	```
77
78	Argument order: always `(expected, actual)` — swapping produces confusing diff output.
79
80	## Advanced Assertions
81
82	```go
83	is.ElementsMatch([]string{"b", "a", "c"}, result) // unordered comparison
84	is.InDelta(3.14, computedPi, 0.01) // float tolerance
85	is.JSONEq(`{"name":"alice"}`, `{"name": "alice"}`) // ignores whitespace/key order
86	is.WithinDuration(expected, actual, 5*time.Second)
87	is.Regexp(`^user-[a-f0-9]+$`, userID)
88
89	// Async polling
90	is.Eventually(func() bool {
91	status, _ := client.GetJobStatus(jobID)
92	return status == "completed"
93	}, 5time.Second, 100time.Millisecond)
94
95	// Async polling with rich assertions
96	is.EventuallyWithT(func(c *assert.CollectT) {
97	resp, err := client.GetOrder(orderID)
98	assert.NoError(c, err)
99	assert.Equal(c, "shipped", resp.Status)
100	}, 10time.Second, 500time.Millisecond)
101	```
102
103	## testify/mock
104
105	Mock interfaces to isolate the unit under test. E

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6 picks

Type