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|
package parser
import (
"fmt"
"mana/ast"
"mana/lexer"
"testing"
)
func TestLetStatements(t *testing.T) {
const input string = `
let x = 5;
let y = 10;
let foobar = 838383;
`
var l *lexer.Lexer = lexer.New(input)
var p *Parser = New(l)
var program *ast.Program = p.ParseProgram()
checkParserErrors(t, p)
if program == nil {
t.Fatalf("ParseProgram() returned nil")
}
if len(program.Statements) != 3 {
t.Fatalf("program.Statements does not contain 3 statements. got=%d", len(program.Statements))
}
var tests = []struct {
expectedIdentifier string
}{
{"x"},
{"y"},
{"foobar"},
}
for i, tt := range tests {
var stmt ast.Statement = program.Statements[i]
if !testLetStatement(t, stmt, tt.expectedIdentifier) {
return
}
}
}
func checkParserErrors(t *testing.T, p *Parser) {
var errors []string = p.Errors()
if len(errors) == 0 {
return
}
t.Errorf("parser has %d errors", len(errors))
for _, msg := range errors {
t.Errorf("parser error: %q", msg)
}
t.FailNow()
}
func testLetStatement(t *testing.T, s ast.Statement, name string) bool {
if s.TokenLiteral() != "let" {
t.Errorf("s.TokenLiteral not 'let'. got=%q", s.TokenLiteral())
return false
}
var letStmt, ok = s.(*ast.LetStatement)
if !ok {
t.Errorf("s not *ast.LetStatement. got=%T", s)
return false
}
if letStmt.Name.Value != name {
t.Errorf("letStmt.Name.Value not '%s'. got=%s", name, letStmt.Name.Value)
return false
}
if letStmt.Name.TokenLiteral() != name {
t.Errorf("letStmt.Name.TokenLiteral() not '%s'. got=%s", name, letStmt.Name.TokenLiteral())
return false
}
return true
}
// Return statement tests.
func TestReturnStatements(t *testing.T) {
var input string = `
return 5;
return 10;
return 993322;
`
var l *lexer.Lexer = lexer.New(input)
var p *Parser = New(l)
var program *ast.Program = p.ParseProgram()
checkParserErrors(t, p)
if len(program.Statements) != 3 {
t.Fatalf("program.Statements does not contain 3 statements. got=%d", len(program.Statements))
}
for _, stmt := range program.Statements {
var returnStmt, ok = stmt.(*ast.ReturnStatement)
if !ok {
t.Errorf("stmt not *ast.ReturnStatement. got=%T", stmt)
continue
}
if returnStmt.TokenLiteral() != "return" {
t.Errorf("returnStmt.TokenLiteral not 'return', got %q", returnStmt.TokenLiteral())
}
}
}
// Identifier expression tests.
func TestIdentifierExpression(t *testing.T) {
var input string = "foobar;"
var l *lexer.Lexer = lexer.New(input)
var p *Parser = New(l)
var program *ast.Program = p.ParseProgram()
checkParserErrors(t, p)
if len(program.Statements) != 1 {
t.Fatalf("program has not enough statements. got=%d", len(program.Statements))
}
stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
if !ok {
t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T", program.Statements[0])
}
ident, ok := stmt.Expression.(*ast.Identifier)
if !ok {
t.Fatalf("exp not *ast.Identifier. got=%T", stmt.Expression)
}
if ident.Value != "foobar" {
t.Errorf("ident.Value not %s. got=%s", "foobar", ident.Value)
}
if ident.TokenLiteral() != "foobar" {
t.Errorf("ident.TokenLiteral not %s. got=%s", "foobar", ident.TokenLiteral())
}
}
// Integer literal expression tests.
func TestIntegerLiteralExpression(t *testing.T) {
var input string = "5;"
var l *lexer.Lexer = lexer.New(input)
var p *Parser = New(l)
var program *ast.Program = p.ParseProgram()
checkParserErrors(t, p)
if len(program.Statements) != 1 {
t.Fatalf("program has not enough statements. got=%d", len(program.Statements))
}
stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
if !ok {
t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T", program.Statements[0])
}
literal, ok := stmt.Expression.(*ast.IntegerLiteral)
if !ok {
t.Fatalf("exp not *ast.IntegerLiteral. got=%T", stmt.Expression)
}
if literal.Value != 5 {
t.Errorf("literal.Value not %d. got=%d", 5, literal.Value)
}
if literal.TokenLiteral() != "5" {
t.Errorf("literal.TokenLiteral not %s. got=%s", "5", literal.TokenLiteral())
}
}
// Prefix expression tests.
func TestParsingPrefixExpressions(t *testing.T) {
var prefixTests = []struct {
input string
operator string
integerValue int64
}{
{"!5;", "!", 5},
{"-15;", "-", 15},
}
for _, tt := range prefixTests {
var l *lexer.Lexer = lexer.New(tt.input)
var p *Parser = New(l)
var program *ast.Program = p.ParseProgram()
checkParserErrors(t, p)
if len(program.Statements) != 1 {
t.Fatalf("program.Statements does not contain %d statements. got=%d", 1, len(program.Statements))
}
stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
if !ok {
t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T", program.Statements[0])
}
exp, ok := stmt.Expression.(*ast.PrefixExpression)
if !ok {
t.Fatalf("stmt is not ast.PrefixExpression. got=%T", stmt.Expression)
}
if exp.Operator != tt.operator {
t.Fatalf("exp.Operator is not '%s'. got=%s", tt.operator, exp.Operator)
}
if !testIntegerLiteral(t, exp.Right, tt.integerValue) {
return
}
}
}
func testIntegerLiteral(t *testing.T, il ast.Expression, value int64) bool {
var integ, ok = il.(*ast.IntegerLiteral)
if !ok {
t.Errorf("il not *ast.IntegerLiteral. got=%T", il)
return false
}
if integ.Value != value {
t.Errorf("integ.Value not %d. got=%d", value, integ.Value)
return false
}
if integ.TokenLiteral() != fmt.Sprintf("%d", value) {
t.Errorf("integ.TokenLiteral not %d. got=%s", value, integ.TokenLiteral())
return false
}
return true
}
|
