remove front or back

remove.go

// remove will remove drop from the start or end of s.
// If drop is not found at front or end of s then the
// original string is returned. If drop occurs at the 
// start and end of s, it will only be dropped from the
// start.
func remove2(s, drop string) string {
	if strings.HasPrefix(s, drop) {
		return strings.TrimPrefix(s, drop)
	}
	return strings.TrimSuffix(s, drop)
}

// or providing an explicit location in the string

// remove will remove drop from the front of s if fromFront is true,
// or from the back of s if false. If drop is not found in the appropriate
// place in s, then the original string is returned.
func remove(s, drop string, fromFront bool) string {
	if fromFront {
		return strings.TrimPrefix(s, drop)
	}
	return strings.TrimSuffix(s, drop)
}

func TestRemove(t *testing.T) {
	tests := []struct {
		name     string
		s        string
		drop     string
		fromFont bool
		expected string
	}{
		{
			name:     "good_front_drop",
			s:        "foo-bar-bad",
			drop:     "foo-",
			fromFont: true,
			expected: "bar-bad",
		},
		{
			name:     "bad_front_drop",
			s:        "foo-bar-bad",
			drop:     "foo-",
			fromFont: false,
			expected: "foo-bar-bad",
		},
		{
			name:     "missing_front_drop",
			s:        "foo-bar-bad",
			drop:     "flo",
			fromFont: true,
			expected: "foo-bar-bad",
		},
		{
			name:     "good_back_drop",
			s:        "foo-bar-bad",
			drop:     "bad",
			fromFont: false,
			expected: "foo-bar-",
		},
		{
			name:     "bad_back_drop",
			s:        "foo-bar-bad",
			drop:     "bad",
			fromFont: true,
			expected: "foo-bar-bad",
		},
		{
			name:     "missing_back_drop",
			s:        "foo-bar-bad",
			drop:     "bod",
			fromFont: false,
			expected: "foo-bar-bad",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := remove(tt.s, tt.drop, tt.fromFont)
			if got != tt.expected {
				t.Errorf("got: %q, expected: %q", got, tt.expected)
			}
		})
	}
}