cmd/relnot: Release notes generator

cmd/relnot/change.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+)
+
+//nolint:gochecknoglobals
+var contributors = map[string]bool{
+	// core team
+	"mstoykov":     true,
+	"codebien":     true,
+	"olegbespalov": true,
+	"oleiade":      true,
+
+	// browser team
+	"ankur22":    true,
+	"inancgumus": true,
+	"ka3de":      true,
+}
+
+type change struct {
+	RawType string
+	Type    PullType
+	Number  int
+	Title   string
+	Body    string
+	Author  string
+}
+
+func (c change) Format() string {
+	if c.isEpic() {
+		return c.formatEpic()
+	}
+	text := fmt.Sprintf("- [#%d](https://github.com/grafana/k6/pull/%d) %s", c.Number, c.Number, c.Title)
+	if c.isExternalContributor() {
+		text += fmt.Sprintf(" Thanks @%s for the contribution!.", c.Author)
+	}
+	return text
+}
+
+func (c change) formatEpic() string {
+	text := fmt.Sprintf("### %s\n\n%s", c.Title, c.Body)
+	if c.isExternalContributor() {
+		text += fmt.Sprintf("\nThanks @%s for the contribution!.", c.Author)
+	}
+	return text + "\n"
+}
+
+func (c change) isEpic() bool {
+	return c.Type == EpicFeature || c.Type == EpicBreaking
+}
+
+func (c change) isExternalContributor() bool {
+	return contributors[c.Author]
+}

cmd/relnot/change_test.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestChangeFormatTypeNoBody(t *testing.T) {
+	t.Parallel()
+	c := change{
+		Type:   Bug,
+		Number: 3231,
+		Title:  "Fixes the tracing module sampling option to default to 1.0 when not set by the user.",
+		Body:   "",
+	}
+	exp := "- [#3231](https://github.com/grafana/k6/pull/3231) Fixes the tracing module sampling option to default to 1.0 when not set by the user."
+	if s := c.Format(); s != exp {
+		t.Errorf("unexpected formatted change: got: %s", s)
+	}
+}

cmd/relnot/main.go

@@ -0,0 +1,272 @@
+// relnot is a tool for generating release notes from the merged
+// in a specific milestone.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+// TODO: It is mostly an MVP, so refactor after we have consensus and we are sure that it makes sense
+//
+//nolint:funlen,gocognit
+func main() {
+	var (
+		// TODO: we may consider to input it as an argument
+		// e.g.
+		// $ relnot -m v0.47.0
+		milestone = "v0.47.0"
+
+		// TODO: we may consider to input it as an argument
+		// e.g.
+		// $ relnot -m v0.47.0 ./release\ notes/unreleased.md
+		unreleasedFilePath = "./../../release notes/unreleased.md"
+	)
+
+	f, err := openUnreleased(unreleasedFilePath)
+	if err != nil {
+		log.Fatalf("open Unreleased file failed: %v", err)
+	}
+	defer func() {
+		_ = f.Close()
+	}()
+
+	fmt.Println("Unreleased file descriptor opened")
+
+	pulls, err := fetchPullRequests(milestone)
+	if err != nil {
+		fmt.Println("Fetch pull requests failed:", err)
+		return
+	}
+
+	if len(pulls) < 1 {
+		fmt.Println("There aren't pull requests to process, the generation will be stopped.")
+		return
+	}
+
+	fmt.Printf("Pull requests fetched: %d\n\n", len(pulls))
+
+	changesByType := make(map[PullType][]change)
+	changesContents := make(map[PullType]string)
+
+	log.Println("Parsing changes from Pull request:")
+	for _, pull := range pulls {
+		fmt.Printf("#%d ", pull.Number)
+
+		var parsedChange change
+		parsedChange, err = parseChange(pull)
+		if err != nil {
+			fmt.Printf("Parse change (#%d) failed: %v\n", parsedChange.Number, err)
+			return
+		}
+
+		changesByType[parsedChange.Type] = append(changesByType[parsedChange.Type], parsedChange)
+		if parsedChange.Type == Undefined {
+			continue
+		}
+
+		text := parsedChange.Format()
+		changesContents[parsedChange.Type] += text + "\n"
+	}
+
+	fmt.Println("\n\nMatching stage report:")
+	for typ, changes := range changesByType {
+		if typ == Undefined {
+			fmt.Printf("Type: %s, Count: %d, Pulls: %v\n", typ, len(changes), mapChangesNumbers(changes))
+			continue
+		}
+		fmt.Printf("Type: %s, Count: %d\n", typ, len(changes))
+	}
+
+	//nolint:forbidigo //we need to access the file
+	ftemp, err := os.CreateTemp("", "")
+	if err != nil {
+		fmt.Println("Open the temporary Unreleased joiner failed:", err)
+		return
+	}
+	defer func() {
+		//nolint:forbidigo
+		_ = os.Remove(ftemp.Name())
+		_ = ftemp.Close()
+	}()
+
+	joiner := bufio.NewWriter(ftemp)
+	scanner := bufio.NewScanner(f)
+
+	for scanner.Scan() {
+		text := scanner.Text()
+		if len(text) < 1 || text[0] != '<' {
+			_, err = joiner.Write([]byte(text + "\n"))
+			if err != nil {
+				fmt.Printf("Failed to write a line copy: %s\n\tthe line: %s\n", err, text)
+				return
+			}
+			continue
+		}
+
+		var typeToAdd PullType
+		typeToAdd, err = typeFromPlaceholder(text)
+		if err != nil {
+			fmt.Printf("Parsing of the placeholder (%q) failed: %s\n", text, err)
+			return
+		}
+
+		changesToAdd, ok := changesContents[typeToAdd]
+		if !ok {
+			_, err = joiner.Write([]byte(placeholder(typeToAdd) + "\n"))
+			if err != nil {
+				fmt.Printf("Failed to write a list of changes for the type %q: %s\n", typeToAdd, err)
+				return
+			}
+			continue
+		}
+
+		_, err = joiner.Write([]byte(changesToAdd + placeholder(typeToAdd) + "\n"))
+		if err != nil {
+			fmt.Println("Failed to write a change item:", err)
+			return
+		}
+	}
+
+	if err = scanner.Err(); err != nil {
+		fmt.Println("Reading of the current version of the Unreleased file failed:", err)
+		return
+	}
+
+	err = joiner.Flush()
+	if err != nil {
+		fmt.Println("\nWARN: The flush operation for the joiner failed:", err)
+	}
+	_ = ftemp.Close()
+
+	//nolint:forbidigo
+	if err := os.Rename(ftemp.Name(), unreleasedFilePath); err != nil {
+		fmt.Println("Moving the new unreleased version failed:", err)
+		return
+	}
+
+	fmt.Println("\nRelease notes generation completed.")
+}
+
+func placeholder(typ PullType) string {
+	return fmt.Sprintf("<%s>", typ.String())
+}
+
+func typeFromPlaceholder(text string) (PullType, error) {
+	text = strings.TrimPrefix(text, "<")
+	text = strings.TrimSuffix(text, ">")
+	return PullTypeString(text)
+}
+
+type pullRequest struct {
+	Number int    `json:"number"`
+	Body   string `json:"body"`
+	Author struct {
+		Username string `json:"login"`
+	} `json:"author"`
+}
+
+func parseChange(p pullRequest) (change, error) {
+	c := change{Number: p.Number}
+	_, changeBody, found := strings.Cut(p.Body, "### Changelog\r\n\r\n")
+	if !found {
+		return c, nil
+	}
+
+	bodyParts := strings.SplitN(changeBody, "\r\n\r\n", 2)
+	firstLine := strings.SplitN(bodyParts[0], ":", 2)
+
+	changeType, err := PullTypeString(strings.ToLower(firstLine[0]))
+	if err != nil {
+		return c, fmt.Errorf("pull request's type parser: %w", err)
+	}
+
+	c.Number = p.Number
+	c.Type = changeType
+	c.Title = strings.Trim(firstLine[1], " ")
+
+	if len(bodyParts) > 1 {
+		c.Body = bodyParts[1]
+	}
+
+	return c, nil
+}
+
+func fetchPullRequests(milestone string) ([]pullRequest, error) {
+	// It requires pager to be set to `cat` => $ gh config set pager cat
+
+	//nolint:gosec //TODO: validation of milestone
+	cmd := exec.Command("gh", "pr", "list", "--repo", "grafana/k6",
+		"-s", "merged",
+		"--search", fmt.Sprintf("milestone:%s sort:created-desc", milestone),
+		"--json", "number,body,author",
+		"--limit", "1000",
+	)
+
+	stdout, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("invoke CLI command: %w", err)
+	}
+
+	var pulls []pullRequest
+	err = json.Unmarshal(stdout, &pulls)
+	if err != nil {
+		return nil, fmt.Errorf("JSON unmarhsal: %w", err)
+	}
+
+	return pulls, err
+}
+
+func mapChangesNumbers(changes []change) []int {
+	nums := make([]int, 0, len(changes))
+	for _, p := range changes {
+		nums = append(nums, p.Number)
+	}
+	return nums
+}
+
+//nolint:forbidigo
+func openUnreleased(path string) (io.ReadCloser, error) {
+	f, err := os.Open(filepath.Clean(path))
+	if os.IsNotExist(err) {
+		return io.NopCloser(bytes.NewBufferString(template)), nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return f, err
+}
+
+//nolint:gochecknoglobals
+var template = `## Breaking changes
+
+<epic-breaking>
+
+<breaking>
+
+## New features
+
+<epic-feature>
+
+<feature>
+
+### UX improvements and enhancements
+
+<ux>
+
+## Bug fixes
+
+<bug>
+
+## Maintenance and internal improvements
+
+<internal>
+`

cmd/relnot/parser_test.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"testing"
+)
+
+func TestParseChange(t *testing.T) {
+	t.Parallel()
+
+	//nolint:forbidigo
+	testdata, err := os.Open("./testdata/pulls.json")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	input, err := io.ReadAll(testdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var pulls []pullRequest
+	err = json.Unmarshal(input, &pulls)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	changes := make([]change, 0, len(pulls))
+	for _, pull := range pulls {
+		change, err := parseChange(pull)
+		if err != nil {
+			t.Fatal(err)
+		}
+		changes = append(changes, change)
+	}
+
+	if len(changes) != 10 {
+		t.Errorf("unexpected identified changes")
+	}
+}