all related to extension strategy renamed to reference it

internal/code-generator/generator/extensions.go

@@ -0,0 +1,54 @@
+package generator
+
+import (
+	"bytes"
+	"io"
+	"strings"
+	"text/template"
+
+	yaml "gopkg.in/yaml.v2"
+)
+
+// Extensions reads from buf and builds extensions_map.go file from extensionsTmplPath.
+func Extensions(data []byte, extensionsTmplPath, extensionsTmplName, commit string) ([]byte, error) {
+	languages := make(map[string]*languageInfo)
+	if err := yaml.Unmarshal(data, &languages); err != nil {
+		return nil, err
+	}
+
+	orderedKeyList := getAlphabeticalOrderedKeys(languages)
+	languagesByExtension := buildExtensionLanguageMap(languages, orderedKeyList)
+
+	buf := &bytes.Buffer{}
+	if err := executeExtensionsTemplate(buf, languagesByExtension, extensionsTmplPath, extensionsTmplName, commit); err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+func buildExtensionLanguageMap(languages map[string]*languageInfo, orderedKeyList []string) map[string][]string {
+	extensionLangsMap := make(map[string][]string)
+	for _, lang := range orderedKeyList {
+		langInfo := languages[lang]
+		for _, extension := range langInfo.Extensions {
+			extensionLangsMap[extension] = append(extensionLangsMap[extension], lang)
+		}
+	}
+
+	return extensionLangsMap
+}
+
+func executeExtensionsTemplate(out io.Writer, languagesByExtension map[string][]string, extensionsTmplPath, extensionsTmpl, commit string) error {
+	fmap := template.FuncMap{
+		"getCommit":         func() string { return commit },
+		"formatStringSlice": func(slice []string) string { return `"` + strings.Join(slice, `","`) + `"` },
+	}
+
+	t := template.Must(template.New(extensionsTmpl).Funcs(fmap).ParseFiles(extensionsTmplPath))
+	if err := t.Execute(out, languagesByExtension); err != nil {
+		return err
+	}
+
+	return nil
+}