fix(init): do not require re-init after explicit init on clean direct…

…ory (#2949)

* fix(init): avoid re-init warning after explicit init

* fix failed test

* fix linter issue

cli/commands/terraform/download_source.go

@@ -130,7 +130,9 @@ func DownloadTerraformSourceIfNecessary(ctx context.Context, terraformSource *te
 	currentVersion, err := terraformSource.EncodeSourceVersion()
 	// if source versions are different or calculating version failed, create file to run init
 	// https://github.com/gruntwork-io/terragrunt/issues/1921
-	if previousVersion != currentVersion || err != nil {
+	if (previousVersion != "" && previousVersion != currentVersion) || err != nil {
+		terragruntOptions.Logger.Debugf("Requesting re-init, source version has changed from %s to %s recently.", previousVersion, currentVersion)
+
 		initFile := util.JoinPath(terraformSource.WorkingDir, ModuleInitRequiredFile)
 
 		f, createErr := os.Create(initFile)

cli/commands/terraform/download_source_test.go

@@ -168,7 +168,7 @@ func TestDownloadTerraformSourceIfNecessaryLocalDirToEmptyDir(t *testing.T) {
 	downloadDir := tmpDir(t)
 	defer os.Remove(downloadDir)
 
-	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, false, "# Hello, World", true)
+	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, false, "# Hello, World", false)
 }
 
 func TestDownloadTerraformSourceIfNecessaryLocalDirToAlreadyDownloadedDir(t *testing.T) {
@@ -190,7 +190,7 @@ func TestDownloadTerraformSourceIfNecessaryRemoteUrlToEmptyDir(t *testing.T) {
 	downloadDir := tmpDir(t)
 	defer os.Remove(downloadDir)
 
-	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, false, "# Hello, World", true)
+	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, false, "# Hello, World", false)
 }
 
 func TestDownloadTerraformSourceIfNecessaryRemoteUrlToAlreadyDownloadedDir(t *testing.T) {
@@ -238,7 +238,7 @@ func TestDownloadTerraformSourceIfNecessaryRemoteUrlOverrideSource(t *testing.T)
 
 	copyFolder(t, "../../../test/fixtures/download-source/hello-world-version-remote", downloadDir)
 
-	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, true, "# Hello, World", true)
+	testDownloadTerraformSourceIfNecessary(t, canonicalURL, downloadDir, true, "# Hello, World", false)
 }
 
 func TestDownloadTerraformSourceIfNecessaryInvalidTerraformSource(t *testing.T) {