feat(output): support output format github-actions (closes editorconf…

…ig-checker#317)

Now one can request `--format github-actions` and get the errors
returned in a format that should be parsable by Github Actions.

I decided against implementing the grouping feature (so errors would be
additionally grouped per file), since nested groups are not yet
supported - actions/toolkit#1001
Doing so would then break the use cases where a linter collection
like mega-linter or super-linter use groups themselves (e.g. to group
errors by linter)

cmd/editorconfig-checker/main.go

@@ -39,8 +39,8 @@ func init() {
 	flag.BoolVar(&c.ShowVersion, "version", false, "print the version number")
 	flag.BoolVar(&c.Help, "help", false, "print the help")
 	flag.BoolVar(&c.Help, "h", false, "print the help")
-	flag.StringVar(&c.Format, "format", "default", "specify the output format: default, gcc")
-	flag.StringVar(&c.Format, "f", "default", "specify the output format: default, gcc")
+	flag.StringVar(&c.Format, "format", "default", "specify the output format: default, gcc, github-actions")
+	flag.StringVar(&c.Format, "f", "default", "specify the output format: default, gcc, github-actions")
 	flag.BoolVar(&c.Verbose, "verbose", false, "print debugging information")
 	flag.BoolVar(&c.Verbose, "v", false, "print debugging information")
 	flag.BoolVar(&c.Debug, "debug", false, "print debugging information")

pkg/error/error.go

@@ -81,6 +81,11 @@ func PrintErrors(errors []ValidationErrors, config config.Config) {
 				continue
 			}
 
+			// for these formats the errors need to be consolidated first.
+			if config.Format == "default" || config.Format == "github-actions" {
+				fileErrors.Errors = ConsolidateErrors(fileErrors.Errors, config)
+			}
+
 			if config.Format == "gcc" {
 				// gcc: A format mimicking the error format from GCC.
 				for _, singleError := range fileErrors.Errors {
@@ -90,10 +95,23 @@ func PrintErrors(errors []ValidationErrors, config config.Config) {
 					}
 					config.Logger.Error(fmt.Sprintf("%s:%d:%d: %s: %s", relativeFilePath, lineNo, 0, "error", singleError.Message))
 				}
+			} else if config.Format == "github-actions" {
+				// github-actions: A format dedicated for usage in Github Actions
+				for _, singleError := range fileErrors.Errors {
+					if singleError.LineNumber != -1 {
+						if singleError.ConsecuitiveCount != 0 {
+							config.Logger.Error(fmt.Sprintf("::error file=%s,line=%d,endLine=%d::%s", relativeFilePath, singleError.LineNumber, singleError.LineNumber+singleError.ConsecuitiveCount, singleError.Message))
+						} else {
+							config.Logger.Error(fmt.Sprintf("::error file=%s,line=%d::%s", relativeFilePath, singleError.LineNumber, singleError.Message))
+						}
+					} else {
+						config.Logger.Error(fmt.Sprintf("::error file=%s::%s", relativeFilePath, singleError.Message))
+					}
+				}
 			} else {
 				// default: A human readable text format.
 				config.Logger.Warning(fmt.Sprintf("%s:", relativeFilePath))
-				for _, singleError := range ConsolidateErrors(fileErrors.Errors, config) {
+				for _, singleError := range fileErrors.Errors {
 					if singleError.LineNumber != -1 {
 						if singleError.ConsecuitiveCount != 0 {
 							config.Logger.Error(fmt.Sprintf("\t%d-%d: %s", singleError.LineNumber, singleError.LineNumber+singleError.ConsecuitiveCount, singleError.Message))

pkg/error/error_test.go

@@ -157,4 +157,7 @@ func TestPrintErrors(t *testing.T) {
 
 	config2 := config.Config{Format: "gcc"}
 	PrintErrors(input, config2)
+
+	config3 := config.Config{Format: "github-actions"}
+	PrintErrors(input, config3)
 }