go-testassert
v0.2.0MIT
Fluent, type-safe test assertions for Go. Built with generics, zero dependencies
$
go get github.com/philiprehberger/go-testassertREADME
go-testassert
Fluent, type-safe test assertions for Go. Built with generics, zero dependencies
Installation
go get github.com/philiprehberger/go-testassert
Usage
import "github.com/philiprehberger/go-testassert"
Generic assertions
testassert.That(t, result).Equals(expected)
testassert.That(t, result).NotEquals(other)
testassert.That[*MyStruct](t, nil).IsNil()
testassert.That(t, ptr).IsNotNil()
Ordered comparisons
testassert.ThatOrdered(t, count).IsGreaterThan(0)
testassert.ThatOrdered(t, score).IsLessThan(100)
testassert.ThatOrdered(t, age).IsGreaterOrEqual(18)
testassert.ThatOrdered(t, temp).IsLessOrEqual(37.5)
Tolerance
testassert.ThatNumeric(t, 3.14).Within(3.0, 0.2) // passes: 2.8 <= 3.14 <= 3.2
testassert.ThatNumeric(t, elapsed).Within(100, 10) // passes if 90 <= elapsed <= 110
String assertions
testassert.ThatString(t, msg).Contains("hello")
testassert.ThatString(t, url).HasPrefix("https://")
testassert.ThatString(t, path).HasSuffix(".go")
testassert.ThatString(t, name).HasLen(5)
testassert.ThatString(t, "").IsEmpty()
testassert.ThatString(t, id).Matches(`^[a-f0-9]{8}$`)
Slice assertions
testassert.ThatSlice(t, items).HasLen(3)
testassert.ThatSlice(t, items).Contains("needle")
testassert.ThatSlice(t, items).IsNotEmpty()
testassert.ThatSlice(t, []int{}).IsEmpty()
Map assertions
testassert.ThatMap(t, m).HasKey("name")
testassert.ThatMap(t, m).HasLen(3)
testassert.ThatMap(t, m).IsNotEmpty()
testassert.ThatMap(t, map[string]int{}).IsEmpty()
Panic assertions
testassert.Panics(t, func() { panic("boom") })
testassert.NotPanics(t, func() { safeOperation() })
Error assertions
testassert.ThatError(t, err).IsNil()
testassert.ThatError(t, err).IsNotNil()
testassert.ThatError(t, err).Is(ErrNotFound)
testassert.ThatError(t, err).Contains("timeout")
var pathErr *PathError
testassert.ThatError(t, err).As(&pathErr)
JSON assertions
testassert.ThatJSON(t, body).Equals(`{"name":"alice","age":30}`)
testassert.ThatJSON(t, body).HasKey("name")
testassert.ThatJSON(t, body).Contains("age", 30)
Custom messages
testassert.That(t, result).WithMessage("user lookup").Equals(expected)
Chaining
All assertions return the receiver, so you can chain calls:
testassert.ThatString(t, msg).
Contains("hello").
HasPrefix("hello").
HasLen(11)
testassert.ThatOrdered(t, n).
IsGreaterThan(0).
IsLessThan(100)
API
Constructors
| Function | Description |
|---|---|
That[T](t, got) | Generic assertion for any type |
ThatOrdered[T](t, got) | Assertion for ordered types (int, float, string) |
ThatNumeric[T](t, got) | Assertion for numeric types with arithmetic checks |
ThatString(t, got) | String-specific assertions |
ThatSlice[T](t, got) | Slice-specific assertions |
ThatMap[K, V](t, got) | Map-specific assertions |
ThatError(t, got) | Error-specific assertions |
ThatJSON(t, got) | JSON string assertions |
Panics(t, fn) | Assert function panics |
NotPanics(t, fn) | Assert function does not panic |
Assertion Methods
| Type | Methods |
|---|---|
Assertion[T] | Equals, NotEquals, IsNil, IsNotNil, WithMessage |
OrderedAssertion[T] | Equals, NotEquals, IsGreaterThan, IsLessThan, IsGreaterOrEqual, IsLessOrEqual |
NumericAssertion[T] | Within |
StringAssertion | Equals, Contains, HasPrefix, HasSuffix, IsEmpty, HasLen, Matches |
SliceAssertion[T] | HasLen, IsEmpty, IsNotEmpty, Contains |
MapAssertion[K, V] | HasKey, HasLen, IsEmpty, IsNotEmpty |
ErrorAssertion | IsNil, IsNotNil, Is, Contains, As |
JSONAssertion | Equals, Contains, HasKey |
Development
go test ./...
go vet ./...
Support
If you find this project useful: