Run validation in the selected module

2026-10-10 02:43:23 +00:00
parent 02896b6e12
commit 8350cbf9c9
17 changed files with 577 additions and 55 deletions
--- a/internal/gotool/owner.go
+++ b/internal/gotool/owner.go
@@ -0,0 +1,136 @@
+package gotool
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Owner lazily discovers and reuses one Go tool while its inherited
+// environment and persistent settings file remain unchanged.
+type Owner struct {
+	directory string
+	tool      *Tool
+	env       map[string]string
+	file      string
+	contents  []byte
+	fileFound bool
+}
+
+// NewOwner creates an operation-local Go tool owner without running Go.
+func NewOwner(directory string) *Owner {
+	return &Owner{directory: directory}
+}
+
+// Acquire returns the operation's Go tool, rediscovering settings when their
+// process or persistent inputs have changed.
+func (owner *Owner) Acquire(ctx context.Context) (*Tool, error) {
+	if owner.tool != nil {
+		changed, err := owner.inputsChanged()
+		if err == nil && !changed {
+			return owner.tool, nil
+		}
+	}
+	if err := owner.discover(ctx); err != nil {
+		return nil, err
+	}
+	return owner.tool, nil
+}
+
+// Refresh checks the owner's inputs after a consumer callback and rediscovers
+// settings when the callback changed the environment or persistent file.
+func (owner *Owner) Refresh(ctx context.Context) error {
+	if owner.tool == nil {
+		return nil
+	}
+	changed, err := owner.inputsChanged()
+	if err == nil && !changed {
+		return nil
+	}
+	return owner.discover(ctx)
+}
+
+func (owner *Owner) discover(ctx context.Context) error {
+	environment := inheritedEnvironment()
+	tool, err := New(ctx, owner.directory)
+	if err != nil {
+		return err
+	}
+	settingsFile, err := resolveSettingsFile(owner.directory, tool.settingsFile)
+	if err != nil {
+		return err
+	}
+	contents, found, err := readSettingsFile(settingsFile)
+	if err != nil {
+		return fmt.Errorf("read Go settings file %q: %w", settingsFile, err)
+	}
+	owner.tool = tool
+	owner.env = environment
+	owner.file = settingsFile
+	owner.contents = contents
+	owner.fileFound = found
+	return nil
+}
+
+func (owner *Owner) inputsChanged() (bool, error) {
+	if !sameEnvironment(owner.env, inheritedEnvironment()) {
+		return true, nil
+	}
+	contents, found, err := readSettingsFile(owner.file)
+	if err != nil {
+		return true, err
+	}
+	return found != owner.fileFound || !bytes.Equal(contents, owner.contents), nil
+}
+
+func inheritedEnvironment() map[string]string {
+	values := make(map[string]string)
+	for _, entry := range os.Environ() {
+		key, value, ok := strings.Cut(entry, "=")
+		if ok {
+			values[key] = value
+		}
+	}
+	return values
+}
+
+func sameEnvironment(left, right map[string]string) bool {
+	if len(left) != len(right) {
+		return false
+	}
+	for key, value := range left {
+		other, ok := right[key]
+		if !ok || other != value {
+			return false
+		}
+	}
+	return true
+}
+
+func resolveSettingsFile(directory, filename string) (string, error) {
+	if filename == "" || filename == "off" {
+		return "", nil
+	}
+	if !filepath.IsAbs(filename) {
+		filename = filepath.Join(directory, filename)
+	}
+	return filepath.Abs(filename)
+}
+
+func readSettingsFile(filename string) ([]byte, bool, error) {
+	if filename == "" {
+		return nil, false, nil
+	}
+	contents, err := os.ReadFile(filename)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, false, nil
+	}
+	if err != nil {
+		return nil, false, err
+	}
+	return contents, true, nil
+}