console: ignore round and curly brackets in strings when determining indentation level

console/console.go

@@ -330,11 +330,11 @@ func (c *Console) Interactive() {
 			// Append the line to the input and check for multi-line interpretation
 			input += line + "\n"
 
-			indents = strings.Count(input, "{") + strings.Count(input, "(") - strings.Count(input, "}") - strings.Count(input, ")")
+			indents = countIndents(input)
 			if indents <= 0 {
 				prompt = c.prompt
 			} else {
-				prompt = strings.Repeat("..", indents*2) + " "
+				prompt = strings.Repeat(".", indents*3) + " "
 			}
 			// If all the needed lines are present, save the command and run
 			if indents <= 0 {
@@ -353,6 +353,49 @@ func (c *Console) Interactive() {
 	}
 }
 
+// countIndents returns the number of identations for the given input.
+// In case of invalid input such as var a = } the result can be negative.
+func countIndents(input string) int {
+	var (
+		indents     = 0
+		inString    = false
+		strOpenChar = ' '   // keep track of the string open char to allow var str = "I'm ....";
+		charEscaped = false // keep track if the previous char was the '\' char, allow var str = "abc\"def";
+	)
+
+	for _, c := range input {
+		switch c {
+		case '\\':
+			// indicate next char as escaped when in string and previous char isn't escaping this backslash
+			if !charEscaped && inString {
+				charEscaped = true
+			}
+		case '\'', '"':
+			if inString && !charEscaped && strOpenChar == c { // end string
+				inString = false
+			} else if !inString && !charEscaped { // begin string
+				inString = true
+				strOpenChar = c
+			}
+			charEscaped = false
+		case '{', '(':
+			if !inString { // ignore brackets when in string, allow var str = "a{"; without indenting
+				indents++
+			}
+			charEscaped = false
+		case '}', ')':
+			if !inString {
+				indents--
+			}
+			charEscaped = false
+		default:
+			charEscaped = false
+		}
+	}
+
+	return indents
+}
+
 // Execute runs the JavaScript file specified as the argument.
 func (c *Console) Execute(path string) error {
 	return c.jsre.Exec(path)

console/console_test.go

@@ -294,3 +294,49 @@ func TestPrettyError(t *testing.T) {
 		t.Fatalf("pretty error mismatch: have %s, want %s", output, want)
 	}
 }
+
+// Tests that tests if the number of indents for JS input is calculated correct.
+func TestIndenting(t *testing.T) {
+	testCases := []struct {
+		input               string
+		expectedIndentCount int
+	}{
+		{`var a = 1;`, 0},
+		{`"some string"`, 0},
+		{`"some string with (parentesis`, 0},
+		{`"some string with newline
+		("`, 0},
+		{`function v(a,b) {}`, 0},
+		{`function f(a,b) { var str = "asd("; };`, 0},
+		{`function f(a) {`, 1},
+		{`function f(a, function(b) {`, 2},
+		{`function f(a, function(b) {
+		     var str = "a)}";
+		  });`, 0},
+		{`function f(a,b) {
+		   var str = "a{b(" + a, ", " + b;
+		   }`, 0},
+		{`var str = "\"{"`, 0},
+		{`var str = "'("`, 0},
+		{`var str = "\\{"`, 0},
+		{`var str = "\\\\{"`, 0},
+		{`var str = 'a"{`, 0},
+		{`var obj = {`, 1},
+		{`var obj = { {a:1`, 2},
+		{`var obj = { {a:1}`, 1},
+		{`var obj = { {a:1}, b:2}`, 0},
+		{`var obj = {}`, 0},
+		{`var obj = {
+			a: 1, b: 2
+		}`, 0},
+		{`var test = }`, -1},
+		{`var str = "a\""; var obj = {`, 1},
+	}
+
+	for i, tt := range testCases {
+		counted := countIndents(tt.input)
+		if counted != tt.expectedIndentCount {
+			t.Errorf("test %d: invalid indenting: have %d, want %d", i, counted, tt.expectedIndentCount)
+		}
+	}
+}