feat(gnovm): Add Basic Code Indentation in REPL

gnovm/cmd/gno/repl.go

@@ -17,9 +17,12 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/commands"
 )
 
-const indentSize = 4
-
 const (
+	indentSize = 4
+
+	importExample = "import \"gno.land/p/demo/avl\""
+	funcExample   = "func a() string { return \"a\" }"
+	printExample  = "println(a())"
 	srcCommand    = "/src"
 	editorCommand = "/editor"
 	resetCommand  = "/reset"
@@ -28,6 +31,18 @@ const (
 	helpCommand   = "/help"
 	gnoREPL       = "gno> "
 	inEditMode    = "...  "
+
+	helpText = `// Usage:
+//   gno> %-35s // import the p/demo/avl package
+//   gno> %-35s // declare a new function named a
+//   gno> %-35s // print current generated source
+//   gno> %-35s // enter in multi-line mode, end with ';'
+//   gno> %-35s // clear the terminal screen
+//   gno> %-35s // remove all previously inserted code
+//   gno> %-35s // print the result of calling a()
+//   gno> %-35s // alternative to <Ctrl-D>
+
+`
 )
 
 type replCfg struct {
@@ -150,31 +165,17 @@ func handleEditor(line string) (string, bool) {
 		return "", false
 	} else if l == editorCommand {
 		fmt.Fprintln(os.Stdout, "// enter a single ';' to quit and commit")
-
 		return "", true
 	}
 
 	return line, false
 }
 
 func updateIndentLevel(line string, indentLevel int) int {
-	openCount, closeCount := 0, 0
-	increaseIndent := false
-
-	for i, char := range line {
-		switch char {
-		case '{', '(', '[':
-			openCount++
-
-			if i < len(line)-1 && line[i+1] == '\n' {
-				increaseIndent = true
-			}
-		case '}', ')', ']':
-			closeCount++
-		}
-	}
-
+	openCount, closeCount := countBrackets(line)
+	increaseIndent := shouldIncreaseIndent(line)
 	indentLevel += openCount - closeCount
+
 	if indentLevel < 0 {
 		indentLevel = 0
 	}
@@ -183,18 +184,57 @@ func updateIndentLevel(line string, indentLevel int) int {
 		indentLevel++
 	}
 
-	if strings.HasSuffix(line, ":") {
-		indentLevel++
+	return indentLevel
+}
+
+func countBrackets(line string) (int, int) {
+	openCount, closeCount := 0, 0
+	inString, inComment, inSingleLineComment := false, false, false
+	var stringChar rune
+
+	for i, char := range line {
+		if !inString && !inComment && !inSingleLineComment {
+			switch char {
+			case '{', '(', '[':
+				openCount++
+			case '}', ')', ']':
+				closeCount++
+			case '"', '\'':
+				inString = true
+				stringChar = char
+			case '/':
+				if i < len(line)-1 {
+					if line[i+1] == '/' {
+						inSingleLineComment = true
+					} else if line[i+1] == '*' {
+						inComment = true
+					}
+				}
+			}
+		} else if inString && char == stringChar {
+			inString = false
+		} else if inComment && i < len(line)-1 && char == '*' && line[i+1] == '/' {
+			inComment = false
+		}
 	}
 
-	return indentLevel
+	return openCount, closeCount
+}
+
+func shouldIncreaseIndent(line string) bool {
+	openIndex := strings.IndexAny(line, "{([")
+	if openIndex != -1 && openIndex < len(line)-1 && line[openIndex+1] == '\n' {
+		return true
+	}
+	return false
 }
 
 func printPrompt(indentLevel int, prev string) {
+	indent := strings.Repeat(" ", indentLevel*indentSize)
 	if prev == "" {
-		fmt.Fprintf(os.Stdout, "gno> %s", strings.Repeat(" ", indentLevel*indentSize))
+		fmt.Fprintf(os.Stdout, "%s%s", gnoREPL, indent)
 	} else {
-		fmt.Fprintf(os.Stdout, "... %s", strings.Repeat(" ", indentLevel*indentSize))
+		fmt.Fprintf(os.Stdout, "%s%s", inEditMode, indent)
 	}
 }
 
@@ -260,14 +300,9 @@ func clearScreen(executor CommandExecutor, osGetter OsGetter) {
 }
 
 func printHelp() {
-	fmt.Fprint(os.Stderr, `// Usage:
-//   gno> import "gno.land/p/demo/avl"     // import the p/demo/avl package
-//   gno> func a() string { return "a" }   // declare a new function named a
-//   gno> /src                             // print current generated source
-//   gno> /editor                          // enter in multi-line mode, end with ';'
-//   gno> /reset                           // remove all previously inserted code
-//   gno> println(a())                     // print the result of calling a()
-//   gno> /exit                            // alternative to <Ctrl-D>
-
-`)
+	fmt.Printf(
+		helpText, importExample, funcExample,
+		srcCommand, editorCommand, clearCommand,
+		resetCommand, exitCommand, printExample,
+	)
 }

gnovm/cmd/gno/repl_test.go

@@ -17,6 +17,7 @@ func TestReplApp(t *testing.T) {
 }
 
 func TestUpdateIndentLevel(t *testing.T) {
+	t.Parallel()
 	tests := []struct {
 		name        string
 		line        string
@@ -45,7 +46,25 @@ func TestUpdateIndentLevel(t *testing.T) {
 			name:        "Test with colon",
 			line:        "case 'a':",
 			indentLevel: 0,
-			want:        1,
+			want:        0,
+		},
+		{
+			name:        "Test with colon and closed bracket",
+			line:        "case 'a': }",
+			indentLevel: 1,
+			want:        0,
+		},
+		{
+			name:        "Test with colon in string",
+			line:        "\"case 'a':\"",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test with colon in string and string end with colon",
+			line:        "case ':':",
+			indentLevel: 0,
+			want:        0,
 		},
 		{
 			name:        "Test with multiple open brackets",
@@ -78,17 +97,55 @@ func TestUpdateIndentLevel(t *testing.T) {
 			want:        1,
 		},
 		{
-			name:        "Test with colon and closed bracket",
-			line:        "case 'a': }",
-			indentLevel: 1,
+			name:        "Test with brackets in string",
+			line:        "\"}}}}\"",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test with brackets in single line comment",
+			line:        "// { [ (",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test with brackets in multi line comment",
+			line:        "/* {{{{ */",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test with brackets in string and comment",
+			line:        "ufmt.Println(\"{ [ ( ) ] } {{\") // { [ ( ) ] ",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test string and single line comment",
+			line:        "CurlyToken = '{' // {",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test curly bracket in string",
+			line:        "a := '{'",
+			indentLevel: 0,
+			want:        0,
+		},
+		{
+			name:        "Test curly bracket in string 2",
+			line:        "a := \"{hello\"",
+			indentLevel: 0,
 			want:        0,
 		},
 	}
 
 	for _, tt := range tests {
+		tt := tt
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
 			if got := updateIndentLevel(tt.line, tt.indentLevel); got != tt.want {
-				t.Errorf("updateIndentLevel() = %v, want %v", got, tt.want)
+				t.Errorf("%s = %v, want %v", tt.name, got, tt.want)
 			}
 		})
 	}
@@ -112,6 +169,7 @@ func (m MockOSGetter) Get() string {
 }
 
 func TestClearScreen(t *testing.T) {
+	t.Parallel()
 	tests := []struct {
 		name     string
 		osGetter OsGetter
@@ -122,7 +180,9 @@ func TestClearScreen(t *testing.T) {
 	}
 
 	for _, tt := range tests {
+		tt := tt
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
 			// Set up the mock executor
 			executor := &MockCommandExecutor{}
 

gnovm/pkg/repl/repl.go

@@ -108,6 +108,11 @@ type Repl struct {
 	stdin     io.Reader
 }
 
+// Read implements io.Reader.
+func (r *Repl) Read(p []byte) (n int, err error) {
+	panic("unimplemented")
+}
+
 // NewRepl creates a Repl struct. It is able to process input source code and eventually run it.
 func NewRepl(opts ...ReplOption) *Repl {
 	t := template.Must(template.New("tmpl").Parse(fileTemplate))