extract concatenated strings (#143)

v2/goi18n/extract_command.go

@@ -167,14 +167,10 @@ func (e *extractor) extractMessage(node ast.Node) {
 		if !ok {
 			continue
 		}
-		value, ok := kve.Value.(*ast.BasicLit)
+		v, ok := extractStringLiteral(kve.Value)
 		if !ok {
 			continue
 		}
-		if value.Kind != token.STRING {
-			continue
-		}
-		v := value.Value[1 : len(value.Value)-1]
 		data[key.Name] = v
 	}
 	if len(data) == 0 {
@@ -187,6 +183,31 @@ func (e *extractor) extractMessage(node ast.Node) {
 	}
 }
 
+func extractStringLiteral(expr ast.Expr) (string, bool) {
+	switch v := expr.(type) {
+	case *ast.BasicLit:
+		if v.Kind != token.STRING {
+			return "", false
+		}
+		return v.Value[1 : len(v.Value)-1], true
+	case *ast.BinaryExpr:
+		if v.Op != token.ADD {
+			return "", false
+		}
+		x, ok := extractStringLiteral(v.X)
+		if !ok {
+			return "", false
+		}
+		y, ok := extractStringLiteral(v.Y)
+		if !ok {
+			return "", false
+		}
+		return x + y, true
+	default:
+		return "", false
+	}
+}
+
 func i18nPackageName(file *ast.File) string {
 	for _, i := range file.Imports {
 		if i.Path.Kind == token.STRING && i.Path.Value == `"github.com/nicksnyder/go-i18n/v2/i18n"` {

v2/goi18n/extract_command_test.go

@@ -136,9 +136,30 @@ two = "Two translation"
 zero = "Zero translation"
 `),
 		},
+		{
+			name: "concat id",
+			file: `package main
+
+			import "github.com/nicksnyder/go-i18n/v2/i18n"
+
+			func main() {
+				_ := &i18n.Message{
+					ID: "Plural" +
+						" " +
+						"ID",
+				}
+			}
+			`,
+			messages: []*i18n.Message{
+				{
+					ID: "Plural ID",
+				},
+			},
+		},
 	}
+
 	for _, test := range tests {
-		t.Run(test.name+"messages", func(t *testing.T) {
+		t.Run(test.name+" messages", func(t *testing.T) {
 			actualMessages, err := extractMessages([]byte(test.file))
 			if err != nil {
 				t.Fatal(err)
@@ -147,7 +168,7 @@ zero = "Zero translation"
 				t.Fatalf("file:\n%s\nexpected: %s\n     got: %s", test.file, marshalTest(test.messages), marshalTest(actualMessages))
 			}
 		})
-		t.Run(test.name+"active file", func(t *testing.T) {
+		t.Run(test.name+" active file", func(t *testing.T) {
 			indir := mustTempDir("TestExtractCommandIn")
 			defer os.RemoveAll(indir)
 			outdir := mustTempDir("TestExtractCommandOut")
@@ -218,7 +239,7 @@ other = "{{.Name}} has {{.UnreadEmailCount}} unread emails."
 }
 
 func marshalTest(value interface{}) string {
-	buf, err := json.Marshal(value)
+	buf, err := json.MarshalIndent(value, "", "  ")
 	if err != nil {
 		panic(err)
 	}