testing: initial code for release helper tool

internal/testing/releasehelper.go

@@ -0,0 +1,143 @@
+// Copyright 2019 The Go Cloud Development Kit Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Helper tool for creating new releases of the Go CDK.
+// Run from the repository root:
+// $ go run internal/testing/releasehelper.go <flags>
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+// TODO(eliben): add bumpversion flag that bumps version by 1, or to a version
+// given on the command line
+var doReplace = flag.Bool("replace", false, "add replace directives to root")
+var doDropReplace = flag.Bool("dropreplace", false, "drop replace directives to root")
+
+// cmdCheck invokes the command given in s, echoing the invocation to stdout.
+// It checks that the command was successful and returns its standard output.
+// If the command returned a non-0 status, log.Fatal is invoked.
+func cmdCheck(s string) []byte {
+	fmt.Printf(" -> %s\n", s)
+	fields := strings.Fields(s)
+	if len(fields) < 1 {
+		log.Fatal("Expected \"command <arguments>\"")
+	}
+	b, err := exec.Command(fields[0], fields[1:]...).Output()
+	if exiterr, ok := err.(*exec.ExitError); ok {
+		log.Fatalf("%s; stderr: %s\n", err, string(exiterr.Stderr))
+	} else if err != nil {
+		log.Fatal("exec.Command", err)
+	}
+	return b
+}
+
+// These types are taken from "go mod help edit", in order to parse the JSON
+// output of `go mod edit -json`.
+type GoMod struct {
+	Module  Module
+	Go      string
+	Require []Require
+	Exclude []Module
+	Replace []Replace
+}
+
+type Module struct {
+	Path    string
+	Version string
+}
+
+type Require struct {
+	Path     string
+	Version  string
+	Indirect bool
+}
+
+type Replace struct {
+	Old Module
+	New Module
+}
+
+// parseModuleInfo parses module information from a go.mod file at path.
+func parseModuleInfo(path string) GoMod {
+	rawJson := cmdCheck("go mod edit -json " + path)
+	var modInfo GoMod
+	err := json.Unmarshal(rawJson, &modInfo)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return modInfo
+}
+
+func runOnGomod(path string) {
+	fmt.Println("Processing", path)
+	modInfo := parseModuleInfo(path)
+
+	for _, r := range modInfo.Require {
+		// Find requirements on modules within the gocloud.dev tree.
+		if strings.HasPrefix(r.Path, "gocloud.dev") {
+			// Find the relative path from 'path' (the module file we're processing)
+			// and the module required here.
+			var reqPath string
+			if r.Path == "gocloud.dev" {
+				reqPath = "."
+			} else {
+				reqPath = r.Path[12:]
+			}
+			rel, err := filepath.Rel(filepath.Dir(path), reqPath)
+			if err != nil {
+				log.Fatal(err)
+			}
+			if strings.HasSuffix(rel, "/.") {
+				rel, _ = filepath.Split(rel)
+			}
+
+			if *doReplace {
+				cmdCheck(fmt.Sprintf("go mod edit -replace=%s=%s %s", r.Path, rel, path))
+			} else if *doDropReplace {
+				cmdCheck(fmt.Sprintf("go mod edit -dropreplace=%s %s", r.Path, path))
+			}
+		}
+	}
+}
+
+func main() {
+	flag.Parse()
+	f, err := os.Open("allmodules")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	input := bufio.NewScanner(f)
+	input.Split(bufio.ScanLines)
+	for input.Scan() {
+		if len(input.Text()) > 0 && !strings.HasPrefix(input.Text(), "#") {
+			runOnGomod(path.Join(input.Text(), "go.mod"))
+		}
+	}
+
+	if input.Err() != nil {
+		log.Fatal(input.Err())
+	}
+}