Monkey/parser/parser_test.go

package parser

import (
	"github/runnignwater/monkey/ast"
	"github/runnignwater/monkey/lexer"
	"testing"
)

/**
 * @Author: simon
 * @Author: ynwdlxm@163.com
 * @Date: 2022/10/2 下午10:40
 * @Desc: LetStatement test case
 */
func TestLetStatements(t *testing.T) {
	input := `
        let x = 5;
        let y = 10;
        let foo = 838383;
        `
	l := lexer.New(input)
	p := New(l)

	program := p.ParseProgram()
	if program == nil {
		t.Fatalf("ParseProgram() return nil")
	}
	if len(program.Statements) != 3 {
		t.Fatalf("Program.Statements does not contain 3 statements. got=%d", len(program.Statements))
	}

	tests := []struct {
		expectedIdentifies string
	}{
		{"x"},
		{"y"},
		{"foo"},
	}

	for i, tt := range tests {
		stmt := program.Statements[i]
		if !testLetStatement(t, stmt, tt.expectedIdentifies) {
			return
		}
	}
}

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
	}

	letStmt, ok := s.(*ast.LetStatement)
	if !ok {
		t.Errorf("s is 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("s.name not '%s. got=%s", name, letStmt.Name)
		return false
	}

	return true
}