From 7bd32bac018d97f45846a5fefcab009bfe910eab Mon Sep 17 00:00:00 2001
From: Paul Cody Johnston <pcj@stack.build>
Date: Thu, 30 Nov 2023 15:44:09 -0700
Subject: [PATCH] Add -scala_gazelle_print_cache_key flag (#108)

---
 language/scala/flags.go      |  5 +++++
 language/scala/flags_test.go | 24 ++++++++++++++++++++++++
 language/scala/language.go   |  2 ++
 3 files changed, 31 insertions(+)

diff --git a/language/scala/flags.go b/language/scala/flags.go
index f311279..cc937ec 100644
--- a/language/scala/flags.go
+++ b/language/scala/flags.go
@@ -23,6 +23,7 @@ const (
 	scalaGazelleCacheFileFlagName        = "scala_gazelle_cache_file"
 	scalaGazelleDebugProcessFileFlagName = "scala_gazelle_debug_process"
 	scalaGazelleCacheKeyFlagName         = "scala_gazelle_cache_key"
+	scalaGazellePrintCacheKeyFlagName    = "scala_gazelle_print_cache_key"
 	cpuprofileFileFlagName               = "cpuprofile_file"
 	memprofileFileFlagName               = "memprofile_file"
 )
@@ -30,6 +31,7 @@ const (
 // RegisterFlags implements part of the language.Language interface
 func (sl *scalaLang) RegisterFlags(flags *flag.FlagSet, cmd string, c *config.Config) {
 	flags.BoolVar(&sl.debugProcessFlagValue, scalaGazelleDebugProcessFileFlagName, false, "if true, prints the process ID and waits for debugger to attach")
+	flags.BoolVar(&sl.printCacheKey, scalaGazellePrintCacheKeyFlagName, true, "if a cache key is set, print the version for auditing purposes")
 	flags.StringVar(&sl.cacheFileFlagValue, scalaGazelleCacheFileFlagName, "", "optional path a cache file (.json or .pb)")
 	flags.StringVar(&sl.cacheKeyFlagValue, scalaGazelleCacheKeyFlagName, "", "optional string that can be used to bust the cache file")
 	flags.StringVar(&sl.cpuprofileFlagValue, cpuprofileFileFlagName, "", "optional path a cpuprofile file (.prof)")
@@ -58,6 +60,9 @@ func (sl *scalaLang) registerConflictResolvers(flags *flag.FlagSet, cmd string,
 
 // CheckFlags implements part of the language.Language interface
 func (sl *scalaLang) CheckFlags(flags *flag.FlagSet, c *config.Config) error {
+	if sl.printCacheKey && sl.cacheKeyFlagValue != "" {
+		fmt.Printf("scala-gazelle: cache v.%s\n", sl.cacheKeyFlagValue)
+	}
 	if sl.debugProcessFlagValue {
 		fmt.Printf("Debugging session requested (Process ID: %d)\n", os.Getpid())
 		fmt.Printf("NOTE: binary must be built with debug symbols for this to work (e.g 'bazel run -c dbg //:gazelle')\n")
diff --git a/language/scala/flags_test.go b/language/scala/flags_test.go
index 56c8783..3239a5b 100644
--- a/language/scala/flags_test.go
+++ b/language/scala/flags_test.go
@@ -48,6 +48,30 @@ func TestCacheFlags(t *testing.T) {
 				}
 			},
 		},
+		"scala_gazelle_print_cache_key_on": {
+			args: []string{
+				"-scala_gazelle_cache_key=12345",
+				"-scala_gazelle_print_cache_key=true",
+			},
+			check: func(t *testing.T, tmpDir string, lang *scalaLang) {
+				if diff := cmp.Diff("12345", lang.cacheKeyFlagValue); diff != "" {
+					t.Errorf("cacheKeyFlagValue (-want got):\n%s", diff)
+				}
+				if diff := cmp.Diff(true, lang.printCacheKey); diff != "" {
+					t.Errorf("printCacheKey (-want got):\n%s", diff)
+				}
+			},
+		},
+		"scala_gazelle_print_cache_key_off": {
+			args: []string{
+				"-scala_gazelle_print_cache_key=false",
+			},
+			check: func(t *testing.T, tmpDir string, lang *scalaLang) {
+				if diff := cmp.Diff(false, lang.printCacheKey); diff != "" {
+					t.Errorf("printCacheKey (-want got):\n%s", diff)
+				}
+			},
+		},
 		"scala_gazelle_cache_key__valid": {
 			files: []testtools.FileSpec{
 				{
diff --git a/language/scala/language.go b/language/scala/language.go
index bdd1cf8..fcc8250 100644
--- a/language/scala/language.go
+++ b/language/scala/language.go
@@ -25,6 +25,8 @@ type scalaLang struct {
 	// debugProcessFlagValue halts processing and prints the PID for attaching a
 	// delve debugger.
 	debugProcessFlagValue bool
+	// optional flag to print the cache key version
+	printCacheKey bool
 	// wantProgress is a flag that prints docker style progress messages if enabled
 	wantProgress bool
 	// cacheFileFlagValue is the main cache file, if enabled