Add support for service selector

Allows the user to select which service specification to output.

Author: Oluwole Fadeyi

cmd/init.go

@@ -69,22 +69,36 @@ func specInitCmd(common *commonoptions.Options) *cobra.Command {
 				options.SourceContent(inputReader),
 				options.Include(opts.IncludedDirs...))
 			if err != nil {
-				logger.Error(err, "parser initialization")
+				logger.Error(err, "Parser initialization")
 				return err
 			}
 
 			services, err := parser.Parse(cmd.Context())
 			if err != nil {
-				logger.Error(err, "parser parsing error")
+				logger.Error(err, "Parser parsing error")
 				return err
 			}
 
 			logger.Info("Source code was parsed")
 
+			// check if the user has selected a target service to output
+			selectedService := services
+			if opts.Service != "" {
+				service, ok := services[opts.Service]
+				if !ok {
+					err := errors.Errorf("selected service %q was not found in the output", opts.Service)
+					logger.Error(err, "")
+					return err
+				}
+				selectedService = map[string]any{}
+				selectedService[opts.Service] = service
+			}
+
+			// Only print to file if the user has selected the to-file option
 			if opts.ToFile {
 				logger.Info("Generating specifications files in output directory.", "directory", generate.DefaultServiceDefinitionDir)
-				if err := generate.WriteSpecifications(nil, []byte(header), services, true, ".", opts.Formats...); err != nil {
-					logger.Error(err, "writing specification error")
+				if err := generate.WriteSpecifications(nil, []byte(header), selectedService, true, ".", opts.Formats...); err != nil {
+					logger.Error(err, "Generating specification file error")
 					return err
 				}
 				return nil
@@ -93,8 +107,8 @@ func specInitCmd(common *commonoptions.Options) *cobra.Command {
 			logger.Info("Printing result specification to stdout.")
 			writer := io.WriteCloser(os.Stdout)
 			defer writer.Close()
-			if err := generate.WriteSpecifications(writer, []byte(header), services, false, "", opts.Formats...); err != nil {
-				logger.Error(err, "writing specification error")
+			if err := generate.WriteSpecifications(writer, []byte(header), selectedService, false, "", opts.Formats...); err != nil {
+				logger.Error(err, "Writing specification to stdout error")
 				return err
 			}
 			return nil

cmd/options/init/README.md

@@ -16,7 +16,7 @@ Package spec contains the different options present under the spec generation co
   - [func (o *Options) Prepare(cmd *cobra.Command) *Options](<#func-options-prepare>)
 
 
-## type [Options](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L19-L26>)
+## type [Options](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L19-L28>)
 
 Options is the list of options/flag available to the application, plus the clients needed by the application to function.
 
@@ -27,27 +27,29 @@ type Options struct {
     Source        string
     SrcLanguage   lang.Target
     Specification string
+    ToFile        bool
+    Service       string
     *common.Options
 }
 ```
 
-### func [New](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L30>)
+### func [New](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L32>)
 
 ```go
 func New(c *common.Options) *Options
 ```
 
 New creates a new instance of the application's options
 
-### func \(\*Options\) [Complete](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L43>)
+### func \(\*Options\) [Complete](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L45>)
 
 ```go
 func (o *Options) Complete() error
 ```
 
 Complete initialises the components needed for the application to function given the options
 
-### func \(\*Options\) [Prepare](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L37>)
+### func \(\*Options\) [Prepare](<https://github.com/tfadeyi/sloth-simple-comments/blob/main/cmd/options/init/options.go#L39>)
 
 ```go
 func (o *Options) Prepare(cmd *cobra.Command) *Options

cmd/options/init/options.go

@@ -23,6 +23,7 @@ type (
 		SrcLanguage   lang.Target
 		Specification string
 		ToFile        bool
+		Service       string
 		*common.Options
 	}
 )
@@ -109,4 +110,10 @@ func (o *Options) addAppFlags(fs *pflag.FlagSet) {
 		false,
 		"Print the generated specifications to file, under ./slo_definitions.",
 	)
+	fs.StringVar(
+		&o.Service,
+		"service",
+		"",
+		"Outputs only the selected service specification from the resulting parsed service specification.",
+	)
 }

internal/generate/README.md

@@ -10,11 +10,20 @@ Package generate contains utilities to generate data from a given specification
 
 ## Index
 
+- [Constants](<#constants>)
 - [Variables](<#variables>)
 - [func IsValidOutputFormat(format string) bool](<#func-isvalidoutputformat>)
 - [func WriteSpecifications(writer io.Writer, header []byte, specs map[string]any, toFile bool, outputDirectory string, formats ...string) error](<#func-writespecifications>)
 
 
+## Constants
+
+DefaultServiceDefinitionDir is the default filename for the output file
+
+```go
+const DefaultServiceDefinitionDir = "slo_definitions"
+```
+
 ## Variables
 
 ErrUnsupportedFormat is returned if the output format is unsupported