test: add large PR review harness

scripts/review-json-field.go

@@ -0,0 +1,46 @@
+//go:build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func main() {
+	if len(os.Args) != 3 {
+		fatal("usage: go run ./scripts/review-json-field.go <review-json> <field.path>")
+	}
+	body, err := os.ReadFile(os.Args[1])
+	if err != nil {
+		fatal("read %s: %v", os.Args[1], err)
+	}
+	var value any
+	if err := json.Unmarshal(body, &value); err != nil {
+		fatal("decode %s: %v", os.Args[1], err)
+	}
+	for _, part := range strings.Split(os.Args[2], ".") {
+		object, ok := value.(map[string]any)
+		if !ok {
+			fatal("field %q is not an object at %q", os.Args[2], part)
+		}
+		next, ok := object[part]
+		if !ok {
+			fatal("field %q missing at %q", os.Args[2], part)
+		}
+		value = next
+	}
+	switch typed := value.(type) {
+	case string:
+		fmt.Println(typed)
+	default:
+		fatal("field %q is %T, want string", os.Args[2], value)
+	}
+}
+
+func fatal(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, "review-json-field: "+format+"\n", args...)
+	os.Exit(1)
+}