Add tags filtering logic

internal/mold/mold.go

@@ -51,6 +51,10 @@ func (m *MoldTemplateVariable) HasTag(tag string) bool {
 	return false
 }
 
+func (m *MoldTemplateVariable) HasTags() bool {
+	return len(m.Tags) > 0
+}
+
 // MoldTemplate data representation for the MoldTemplate.
 type MoldTemplate struct {
 	variables []MoldTemplateVariable
@@ -59,7 +63,7 @@ type MoldTemplate struct {
 }
 
 // New creates a new MoldTemplate from an io.Reader. Use the helper functions to read from the respective input.
-func New(r io.Reader) (*MoldTemplate, error) {
+func New(r io.Reader, tags *[]string) (*MoldTemplate, error) {
 	b, err := io.ReadAll(r)
 	if err != nil {
 		return nil, err
@@ -76,6 +80,21 @@ func New(r io.Reader) (*MoldTemplate, error) {
 			return nil, ErrMissingVariableName
 		}
 
+		var skipEnvVar bool
+		if tags != nil && moldTemplateVariable.HasTags() {
+			skipEnvVar = true
+			for _, tag := range *tags {
+				if moldTemplateVariable.HasTag(tag) {
+					skipEnvVar = false
+					break
+				}
+			}
+		}
+
+		if skipEnvVar {
+			continue
+		}
+
 		// Check for type constraint on the value field
 		switch moldTemplateVariable.Value.(type) {
 		case int, float32, float64:

internal/mold/mold_test.go

@@ -18,7 +18,7 @@ func TestMoldNew(t *testing.T) {
   required: false
 `
 
-	if _, err := New(strings.NewReader(moldTemplate)); err != nil {
+	if _, err := New(strings.NewReader(moldTemplate), nil); err != nil {
 		t.Errorf("Failed to create new mold: %v", err)
 		return
 	}
@@ -37,7 +37,7 @@ func TestCheckKeysInMold(t *testing.T) {
   required: false
 `
 
-	mold, err := New(strings.NewReader(moldTemplate))
+	mold, err := New(strings.NewReader(moldTemplate), nil)
 	if err != nil {
 		t.Errorf("Failed to create new mold: %v", err)
 		return
@@ -75,7 +75,7 @@ func TestVerifyTypeConstraint(t *testing.T) {
   required: false
 `
 
-	if _, err := New(strings.NewReader(moldTemplate)); err != ErrInvalidDataType {
+	if _, err := New(strings.NewReader(moldTemplate), nil); err != ErrInvalidDataType {
 		t.Errorf("Failed to create new mold: %v", err)
 		return
 	}
@@ -94,7 +94,7 @@ func TestMoldPromptReader(t *testing.T) {
   required: false
 `
 
-	m, err := New(strings.NewReader(moldTemplate))
+	m, err := New(strings.NewReader(moldTemplate), nil)
 	if err != nil {
 		t.Errorf("Failed to create new mold: %v", err)
 		return
@@ -145,7 +145,7 @@ func TestHasTag(t *testing.T) {
   required: false
 `
 
-	m, err := New(strings.NewReader(moldTemplate))
+	m, err := New(strings.NewReader(moldTemplate), nil)
 	if err != nil {
 		t.Errorf("Failed to create new mold: %v", err)
 		return
@@ -187,7 +187,7 @@ func TestTagsAll(t *testing.T) {
   required: false
 `
 
-	m, err := New(strings.NewReader(moldTemplate))
+	m, err := New(strings.NewReader(moldTemplate), nil)
 	if err != nil {
 		t.Errorf("Failed to create new mold: %v", err)
 		return

main.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"log"
 	"os"
+	"strings"
 
 	"github.com/0verbyte/envmold/internal/mold"
 )
@@ -25,12 +26,14 @@ var (
 	moldTemplate string
 	outputWriter string
 	debug        bool
+	tags         string
 )
 
 func init() {
 	flag.StringVar(&moldTemplate, "template", "mold.yaml", "Path to the mold environment template file")
 	flag.StringVar(&outputWriter, "output", "stdout", "Where environment variables will be written. File path or stdout")
 	flag.BoolVar(&debug, "debug", false, "Enables debug logging")
+	flag.StringVar(&tags, "tags", "", "Filter environment variables matching tags")
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "Usage of %s (%s):\n", appName, appVersionString())
 		flag.PrintDefaults()
@@ -47,7 +50,7 @@ func appVersionString() string {
 }
 
 func createMold(r io.Reader) (*mold.MoldTemplate, error) {
-	m, err := mold.New(r)
+	m, err := mold.New(r, getTags())
 	if err != nil {
 		return nil, err
 	}
@@ -66,6 +69,14 @@ func getMoldEnvironmentWriter(writerType string) mold.Writer {
 	}
 }
 
+func getTags() *[]string {
+	if tags == "" {
+		return nil
+	}
+	s := strings.Split(tags, ",")
+	return &s
+}
+
 func main() {
 	log.Printf("Running %s (%s)\n", appName, appVersionString())
 

testdata/mold.simple.yaml

@@ -2,6 +2,7 @@
   value: "bar"
   type: string
   required: false
+  tags: [production]
 
 - name: bar
   value: "bar foo bar"
@@ -12,6 +13,9 @@
   value: true
   type: boolean
   required: false
+  tags:
+    - local
+    - dev
 
 - name: baseNumber
   value: 10
@@ -22,3 +26,4 @@
   value: 1.10
   type: number
   required: false
+  tags: ["local", "test"]