feat: include a warning about generated files when generating files 💪 (…

…#33)

I recently landed myself in an `id_gen.go` file using IDE's Go To Definition and started making updates, not noticing that it was a generated file.

This preamble would probably not help me because the file was long but perhaps it will help someone else. 🤷‍♂️

Co-authored-by: Tomas Zahradnicek <[email protected]>

CHANGELOG.md

@@ -7,6 +7,7 @@ How to release a new version:
 ### Added
 - Use `debug.ReadBuildInfo` to get correct version.
 - Print to stderr on error.
+- `gen_id` now includes a comment at the top of the generated file to warn developers that the file is, in fact, generated.
 
 ### Removed
 - `openapi compose`, `repo init`, `repo template` commands.

cmd/tea/gen_id.go

@@ -17,6 +17,7 @@ import (
 )
 
 var (
+	outputPreamble = "// Code generated by tea. DO NOT EDIT.\n\n"
 	// genIDCmd represents the id command
 	genIDCmd = &cobra.Command{
 		Use:   "id",
@@ -134,6 +135,10 @@ func (i IDs) generate() ([]byte, error) {
 	var genData []byte
 	var err error
 
+	if _, err = output.WriteString(outputPreamble); err != nil {
+		return nil, fmt.Errorf("writing output preamble: %w", err)
+	}
+
 	for typ := range i {
 		//nolint:gocritic,exhaustive
 		switch typ {