deduplicate files and don't use values files as templates

main.go

@@ -18,6 +18,27 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
+type StrSet map[string]struct{}
+
+func (s *StrSet) Add(str string) {
+	(*s)[str] = struct{}{}
+}
+
+func (s *StrSet) Has(str string) bool {
+	if _, ok := (*s)[str]; ok {
+		return true
+	}
+	return false
+}
+
+func (s *StrSet) AddHas(str string) bool {
+	if ok := s.Has(str); ok {
+		return ok
+	}
+	s.Add(str)
+	return false
+}
+
 type valFileSlice []string
 
 func (v *valFileSlice) String() string {
@@ -72,11 +93,39 @@ func checkErr(err error) {
 
 func expandFiles(files []string) (expFiles []string) {
 	expFiles = []string{}
+	fileSet := StrSet{}
+	directories := []string{}
+
+	// Ensure we don't process any provided values files as templates.
+	for _, path := range flags.valuesFiles {
+		abs, err := filepath.Abs(path)
+		if err != nil {
+			fileSet.Add(path)
+			break
+		}
+		fileSet.Add(abs)
+	}
+
 	for _, path := range files {
 		fileInfo, err := os.Stat(path)
 		checkErr(err)
 
 		if fileInfo.IsDir() {
+			// When provided path is a directory, defer loading files from it.
+			directories = append(directories, path)
+		} else {
+			abs, err := filepath.Abs(path)
+			if err != nil {
+				// On failure to find the absolute path, just use the provided path.
+				abs = path
+			}
+			// Deduplicate files.
+			if ok := fileSet.AddHas(abs); !ok {
+				expFiles = append(expFiles, path)
+			}
+		}
+		// Walk each provided directory to find templates.
+		for _, path := range directories {
 			filepath.WalkDir(path, func(path string, d fs.DirEntry, err error) error {
 				if err != nil {
 					fmt.Fprintf(os.Stderr, "WARN: %+v", err)
@@ -85,11 +134,17 @@ func expandFiles(files []string) (expFiles []string) {
 				if d.IsDir() {
 					return nil
 				}
-				expFiles = append(expFiles, path)
+				abs, err := filepath.Abs(path)
+				if err != nil {
+					// On failure to find the absolute path, just use the provided path.
+					abs = path
+				}
+				// Deduplicate files.
+				if ok := fileSet.AddHas(abs); !ok {
+					expFiles = append(expFiles, path)
+				}
 				return nil
 			})
-		} else {
-			expFiles = append(expFiles, path)
 		}
 	}
 	return
@@ -111,14 +166,12 @@ func mergeValues() (result map[string]interface{}) {
 	for _, v := range flags.values {
 		valueMap := map[string]interface{}{}
 		subMap := valueMap
-		// fmt.Fprintf(os.Stderr, "113: %+v\n", subMap)
 		for i, node := range v.address {
 			if i == len(v.address)-1 {
 				subMap[node] = v.v
 				break
 			}
 			subMap[node] = map[string]interface{}{}
-			// fmt.Fprintf(os.Stderr, "120: %+v\n", subMap)
 			subMap = subMap[node].(map[string]interface{})
 		}
 		mergemap.Merge(result, valueMap)
@@ -129,7 +182,10 @@ func mergeValues() (result map[string]interface{}) {
 func main() {
 	var err error
 	tpl := template.New("base").Funcs(sprig.FuncMap())
+
 	if len(flag.Args()) == 0 {
+		// With no provided arguments read from STDIN if anything is immediately available through it.
+		// otherwise print the usage and exit.
 		ch := make(chan struct{})
 		go func() {
 			select {
@@ -142,20 +198,24 @@ func main() {
 		}()
 		var data []byte
 		data, err = io.ReadAll(os.Stdin)
+		// Tell the waiting routine that we got input on STDIN.
 		ch <- struct{}{}
 		checkErr(err)
 		tpl, err = tpl.Parse(string(data))
 		checkErr(err)
 	} else if len(flag.Args()) == 1 && flag.Args()[0] == "-" {
+		// If only a single non-flag argument is provided and it's a -, wait for STDIN indefinitely.
 		var data []byte
 		data, err = io.ReadAll(os.Stdin)
 		checkErr(err)
 		tpl, err = tpl.Parse(string(data))
 		checkErr(err)
 	} else {
+		// Otherwise use the provided files/directories for templates to render.
+		// fmt.Fprintf(os.Stderr, "%+v\n", expandFiles(flag.Args()))
 		tpl, err = tpl.ParseFiles(expandFiles(flag.Args())...)
 		checkErr(err)
 	}
-	fmt.Fprintf(os.Stderr, "%+v\n", mergeValues())
+	// fmt.Fprintf(os.Stderr, "%+v\n", mergeValues())
 	tpl.Execute(os.Stdout, mergeValues())
 }