firasdarwish/ore

// assert2 package add missing assertions from testify/assert package
package assert2

import (
    "fmt"
    "runtime/debug"
    "strings"

    "github.com/stretchr/testify/assert"
)

type tHelper interface {
    Helper()
}

type StringMatcher = func(s string) bool

// PanicsWithError asserts that the code inside the specified PanicTestFunc
// panics, and that the recovered panic value is an error that satisfies the
// StringMatcher.
//
//    assert.PanicsWithError(t, ErrorStartsWith("crazy error"), func(){ GoCrazy() })
func PanicsWithError(t assert.TestingT, errStringMatcher StringMatcher, f assert.PanicTestFunc, msgAndArgs ...interface{}) bool {
    if h, ok := t.(tHelper); ok {
        h.Helper()
    }
    funcDidPanic, panicValue, panickedStack := didPanic(f)
    if !funcDidPanic {
        return assert.Fail(t, fmt.Sprintf("func %#v should panic\n\tPanic value:\t%#v", f, panicValue), msgAndArgs...)
    }
    panicErr, ok := panicValue.(error)
    if !ok || !errStringMatcher(panicErr.Error()) {
        return assert.Fail(t, fmt.Sprintf("func %#v panic with unexpected Panic value:\t%#v\n\tPanic stack:\t%s", f, panicValue, panickedStack), msgAndArgs...)
    }

    return true
}

func ErrorStartsWith(prefix string) StringMatcher {
    return func(s string) bool {
        return strings.HasPrefix(s, prefix)
    }
}

func ErrorEndsWith(suffix string) StringMatcher {
    return func(s string) bool {
        return strings.HasSuffix(s, suffix)
    }
}

func ErrorContains(substr string) StringMatcher {
    return func(s string) bool {
        return strings.Contains(s, substr)
    }
}

// didPanic returns true if the function passed to it panics. Otherwise, it returns false.
func didPanic(f assert.PanicTestFunc) (didPanic bool, message interface{}, stack string) {
    didPanic = true

    defer func() {
        message = recover()
        if didPanic {
            stack = string(debug.Stack())
        }
    }()

    // call the target function
    f()
    didPanic = false

    return
}