package assert_test import ( "fmt" "regexp" "testing" "gotest.tools/assert" "gotest.tools/assert/cmp" ) var t = &testing.T{} func ExampleAssert_customComparison() { regexPattern := func(value string, pattern string) cmp.Comparison { return func() cmp.Result { re := regexp.MustCompile(pattern) if re.MatchString(value) { return cmp.ResultSuccess } return cmp.ResultFailure( fmt.Sprintf("%q did not match pattern %q", value, pattern)) } } assert.Assert(t, regexPattern("12345.34", `\d+.\d\d`)) }