utils.go

package texit

import (
	"errors"
	"runtime"
	"strings"
)

// ErrTestFuncNameNotFound error in the case of no testing function was found by `func_name` function
var ErrTestFuncNameNotFound = errors.New("Test function name has not found")

// Returns the name of testing function
// An error is returned if no testing function is found
// (this function call is not in the call graph of a testing function)
func testFuncName() (string, int, error) {
	// Program counter
	var pc uintptr = 1

	// Populate the stack trace starting to 1 cause 0 is this function (`func_name`)
	for i := 1; pc != 0; i++ {
		// Retrieve runtime informations
		ptr, _, _, ok := runtime.Caller(i)
		pc = ptr

		// If there isn't significant information, go to next level
		if (pc == 0) || (!ok) {
			continue
		}

		// Retrieve called function
		f := runtime.FuncForPC(pc)

		// Get the current functiont name
		name := f.Name()

		// Extract the short name by subtracting the package name
		idx := strings.LastIndexByte(f.Name(), '.')
		if idx > 0 {
			name = name[(idx + 1):]
		}

		// Get line in file to have unique position in caller
		_, line := f.FileLine(pc)

		// If the prefix of the function is "Test"
		if strings.HasPrefix(name, "Test") {
			// So, it's a testing function
			return name, line, nil
		}
	}

	// Returns an error if no testing function was found
	return "", 0, ErrTestFuncNameNotFound
}