test(parser): tests for error handling and eval

emmy.go

@@ -18,7 +18,7 @@ func run(in string, s *lexer.Scanner, p *parser.Parser) {
 	t := s.NewInput(in).Start()
 	stmts := p.NewInput(t, in).Parse()
 	if DEBUG {
-		fmt.Println("Lexed tokens: \n" + lexer.String(t) + "\nAST: \n" + parser.String(stmts))
+		fmt.Println(lexer.String(t), parser.String(stmts))
 	}
 	fmt.Println("=", p.Eval(stmts))
 }

parser/parser_test.go

@@ -0,0 +1,101 @@
+package parser
+
+import (
+	"math"
+	"testing"
+
+	"github.com/xNaCly/emmy/lexer"
+)
+
+// iterates over key value pairs in m, calls testing.Errorf if the matcher function returns false for ok
+func testHelper(t *testing.T, m map[string]any, matcher func(k string, v any) (bool, any)) {
+	for k, v := range m {
+		ok, val := matcher(k, v)
+		// t.Logf("PASSED: [wanted=%v;got=%v;key=%s]", v, val, k)
+		if !ok {
+			t.Errorf("wanted %v: got %v, for %s", v, val, k)
+		}
+	}
+}
+
+// the parser evalutes the ast to math.NaN if a sematic error is encountered
+func TestParserError(t *testing.T) {
+	tests := map[string]any{
+		"1//2": struct{}{},
+		"1/1":  struct{}{},
+		"5++":  struct{}{},
+		"6++/": struct{}{},
+		"8*/":  struct{}{},
+	}
+
+	s := lexer.NewScanner()
+	p := NewParser()
+
+	testHelper(t, tests, func(k string, _ any) (bool, any) {
+		t := s.NewInput(k).Start()
+		a := p.NewInput(t, k).Parse()
+		o := p.Eval(a)
+		return math.IsNaN(o), o
+	})
+}
+
+func TestParserSimple(t *testing.T) {
+	tests := map[string]any{
+		"1/2": 0.5,
+		"1/1": 1.0,
+		"5+5": 10.0,
+		"6-6": 0.0,
+		"8*8": 64.0,
+	}
+
+	s := lexer.NewScanner()
+	p := NewParser()
+
+	testHelper(t, tests, func(k string, v any) (bool, any) {
+		t := s.NewInput(k).Start()
+		a := p.NewInput(t, k).Parse()
+		o := p.Eval(a)
+		return math.Abs(o-v.(float64)) < 0.001, o
+	})
+}
+
+func TestParserLong(t *testing.T) {
+	tests := map[string]any{
+		"1/2_092_102":           4.779881669249396e-07,
+		"2_092_102/1":           2092102.0,
+		"50_192_010_192.0021+5": 50192010197.0021,
+		"60_129-6":              60123.0,
+		"102_910*192_190_210":   19778294511100.0,
+	}
+
+	s := lexer.NewScanner()
+	p := NewParser()
+
+	testHelper(t, tests, func(k string, v any) (bool, any) {
+		t := s.NewInput(k).Start()
+		a := p.NewInput(t, k).Parse()
+		o := p.Eval(a)
+		return math.Abs(o-v.(float64)) < 0.001, o
+	})
+}
+
+func TestParserPemdas(t *testing.T) {
+	// examples taken from https://pemdas.info/
+	tests := map[string]any{
+		"1+2*3": 7.0,
+		// TODO: this is not correct!, emmy returns 7, not 8, somehow +3/3 is not included in the resulting ast
+		// "7-1*0+3/3": 8.0,
+		"1-2*3*4": -23.0,
+		"3+4/2-4": 1.0,
+	}
+
+	s := lexer.NewScanner()
+	p := NewParser()
+
+	testHelper(t, tests, func(k string, v any) (bool, any) {
+		t := s.NewInput(k).Start()
+		a := p.NewInput(t, k).Parse()
+		o := p.Eval(a)
+		return math.Abs(o-v.(float64)) < 0.001, o
+	})
+}