test, integration: Add an integration test framework

This adds an initial implementation of an integration test framework for
writing more complicated tests. In particular this also makes some small
additions to the mgmt core so that testing is easier.

integration/util.go

@@ -0,0 +1,75 @@
+// Mgmt
+// Copyright (C) 2013-2018+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package integration
+
+import (
+	"fmt"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+const (
+	binaryName = "mgmt"
+)
+
+// BinaryPath returns the full path to an mgmt binary. It expects that someone
+// will run `make build` or something equivalent to produce a binary before this
+// function runs.
+func BinaryPath() (string, error) {
+	_, file, _, ok := runtime.Caller(0)
+	if !ok {
+		return "", fmt.Errorf("can't determine binary path")
+	}
+	dir := filepath.Dir(file) // dir that this file is contained in
+	root := filepath.Dir(dir) // we're in the parent dir to that
+
+	return path.Join(root, binaryName), nil
+}
+
+// Code takes a code block as a backtick enclosed `heredoc` and removes any
+// common indentation from each line. This helps inline code as strings to be
+// formatted nicely without unnecessary indentation. It also drops the very
+// first line of code if it has zero length.
+func Code(code string) string {
+	output := []string{}
+	lines := strings.Split(code, "\n")
+	var found bool
+	var strip string // prefix to remove
+	for i, x := range lines {
+		if !found && len(x) > 0 {
+			for j := 0; j < len(x); j++ {
+				if x[j] != '\t' {
+					break
+				}
+				strip += "\t"
+			}
+			// otherwise, there's no indentation
+			found = true
+		}
+		if i == 0 && len(x) == 0 { // drop first line if it's empty
+			continue
+		}
+
+		s := strings.TrimPrefix(x, strip)
+		output = append(output, s)
+	}
+
+	return strings.Join(output, "\n")
+}