Merge pull request google#8 from jbeda/parser

Finish writing unit tests for parser

ast.go

@@ -20,40 +20,7 @@ import (
 	"fmt"
 )
 
-// type astKind int
-
-// const (
-// 	astApply astKind = iota
-// 	astArray
-// 	astArrayComprehension
-// 	astArrayComprehensionSimple
-// 	astAssert
-// 	astBinary
-// 	astBuiltinFunction
-// 	astConditional
-// 	astDollar
-// 	astError
-// 	astFunction
-// 	astImport
-// 	astImportstr
-// 	astIndex
-// 	astLocal
-// 	astLiteralBoolean
-// 	astLiteralNull
-// 	astLiteralNumber
-// 	astLiteralString
-// 	astObject
-// 	astDesugaredObject
-// 	astObjectComprehension
-// 	astObjectComprehensionSimple
-// 	astSelf
-// 	astSuperIndex
-// 	astUnary
-// 	astVar
-// )
-
 // identifier represents a variable / parameter / field name.
-
 //+gen set
 type identifier string
 type identifiers []identifier

lexer_test.go

@@ -43,7 +43,7 @@ var lexTests = []lexTest{
 	{"colon3", ":::", tokens{{kind: tokenOperator, data: ":::"}}, ""},
 	{"arrow right", "->", tokens{{kind: tokenOperator, data: "->"}}, ""},
 	{"less than minus", "<-", tokens{{kind: tokenOperator, data: "<"},
-                                     {kind: tokenOperator, data: "-"}}, ""},
+		{kind: tokenOperator, data: "-"}}, ""},
 	{"comma", ",", tokens{{kind: tokenComma, data: ","}}, ""},
 	{"dollar", "$", tokens{{kind: tokenDollar, data: "$"}}, ""},
 	{"dot", ".", tokens{{kind: tokenDot, data: "."}}, ""},

parser.go

@@ -24,10 +24,9 @@ import (
 type precedence int
 
 const (
-	applyPrecedence      precedence = 2  // Function calls and indexing.
-	unaryPrecedence      precedence = 4  // Logical and bitwise negation, unary + -
-	beforeElsePrecedence precedence = 15 // True branch of an if.
-	maxPrecedence        precedence = 16 // Local, If, Import, Function, Error
+	applyPrecedence precedence = 2  // Function calls and indexing.
+	unaryPrecedence precedence = 4  // Logical and bitwise negation, unary + -
+	maxPrecedence   precedence = 16 // Local, If, Import, Function, Error
 )
 
 var bopPrecedence = map[binaryOp]precedence{
@@ -116,7 +115,7 @@ func (p *parser) parseIdentifierList(elementKind string) (identifiers, bool, err
 	for _, n := range exprs {
 		v, ok := n.(*astVar)
 		if !ok {
-			return identifiers{}, false, makeStaticError(fmt.Sprintf("Not an identifier: %v", n), *n.Loc())
+			return identifiers{}, false, makeStaticError(fmt.Sprintf("Expected simple identifier but got a complex expression."), *n.Loc())
 		}
 		ids = append(ids, v.id)
 	}
@@ -189,6 +188,9 @@ func (p *parser) parseBind(binds *astLocalBinds) error {
 		})
 	} else {
 		_, err = p.popExpectOp("=")
+		if err != nil {
+			return err
+		}
 		body, err := p.parse(maxPrecedence)
 		if err != nil {
 			return err
@@ -248,7 +250,6 @@ func (p *parser) parseObjectRemainder(tok *token) (astNode, *token, error) {
 	literalFields := make(literalFieldSet)
 	binds := make(identifierSet)
 
-	_ = "breakpoint"
 	gotComma := false
 	first := true
 
@@ -914,6 +915,7 @@ func (p *parser) parse(prec precedence) (astNode, error) {
 			// the operator.
 			switch p.peek().kind {
 			case tokenOperator:
+				_ = "breakpoint"
 				if p.peek().data == ":" {
 					// Special case for the colons in assert. Since COLON is no-longer a
 					// special token, we have to make sure it does not trip the
@@ -939,8 +941,74 @@ func (p *parser) parse(prec precedence) (astNode, error) {
 			default:
 				return lhs, nil
 			}
-		}
 
+			op := p.pop()
+			switch op.kind {
+			case tokenBracketL:
+				index, err := p.parse(maxPrecedence)
+				if err != nil {
+					return nil, err
+				}
+				end, err := p.popExpect(tokenBracketR)
+				if err != nil {
+					return nil, err
+				}
+				lhs = &astIndex{
+					astNodeBase: astNodeBase{loc: locFromTokens(begin, end)},
+					target:      lhs,
+					index:       index,
+				}
+			case tokenDot:
+				fieldID, err := p.popExpect(tokenIdentifier)
+				if err != nil {
+					return nil, err
+				}
+				id := identifier(fieldID.data)
+				lhs = &astIndex{
+					astNodeBase: astNodeBase{loc: locFromTokens(begin, fieldID)},
+					target:      lhs,
+					id:          &id,
+				}
+			case tokenParenL:
+				end, args, gotComma, err := p.parseCommaList(tokenParenR, "function argument")
+				if err != nil {
+					return nil, err
+				}
+				tailStrict := false
+				if p.peek().kind == tokenTailStrict {
+					p.pop()
+					tailStrict = true
+				}
+				lhs = &astApply{
+					astNodeBase:   astNodeBase{loc: locFromTokens(begin, end)},
+					target:        lhs,
+					arguments:     args,
+					trailingComma: gotComma,
+					tailStrict:    tailStrict,
+				}
+			case tokenBraceL:
+				obj, end, err := p.parseObjectRemainder(op)
+				if err != nil {
+					return nil, err
+				}
+				lhs = &astApplyBrace{
+					astNodeBase: astNodeBase{loc: locFromTokens(begin, end)},
+					left:        lhs,
+					right:       obj,
+				}
+			default:
+				rhs, err := p.parse(prec - 1)
+				if err != nil {
+					return nil, err
+				}
+				lhs = &astBinary{
+					astNodeBase: astNodeBase{loc: locFromTokenAST(begin, rhs)},
+					left:        lhs,
+					op:          bop,
+					right:       rhs,
+				}
+			}
+		}
 	}
 }
 

parser_test.go

@@ -15,21 +15,210 @@ limitations under the License.
 */
 package jsonnet
 
-import (
-	"fmt"
-	"testing"
+import "testing"
 
-	"github.com/kr/pretty"
-)
+var tests = []string{
+	`true`,
+	`1`,
+	`1.2e3`,
+	`!true`,
+	`null`,
+
+	`$.foo.bar`,
+	`self.foo.bar`,
+	`super.foo.bar`,
+	`super[1]`,
+	`error "Error!"`,
+
+	`"world"`,
+	`'world'`,
+	`|||
+   world
+|||`,
+
+	`foo(bar)`,
+	`foo(bar) tailstrict`,
+	`foo.bar`,
+	`foo[bar]`,
+
+	`true || false`,
+	`0 && 1 || 0`,
+	`0 && (1 || 0)`,
+
+	`local foo = "bar"; foo`,
+	`local foo(bar) = bar; foo(1)`,
+	`{ local foo = "bar", baz: 1}`,
+	`{ local foo(bar) = bar, baz: foo(1)}`,
+
+	`{ foo(bar, baz): bar+baz }`,
+
+	`{ ["foo" + "bar"]: 3 }`,
+	`{ ["field" + x]: x for x in [1, 2, 3] }`,
+	`{ local y = x, ["field" + x]: x for x in [1, 2, 3] }`,
+	`{ ["field" + x]: x for x in [1, 2, 3] if x <= 2 }`,
+	`{ ["field" + x + y]: x + y for x in [1, 2, 3] if x <= 2 for y in [4, 5, 6]}`,
+
+	`[]`,
+	`[a, b, c]`,
+	`[x for x in [1,2,3] ]`,
+	`[x for x in [1,2,3] if x <= 2]`,
+	`[x+y for x in [1,2,3] if x <= 2 for y in [4, 5, 6]]`,
+
+	`{}`,
+	`{ hello: "world" }`,
+	`{ hello +: "world" }`,
+	`{
+  hello: "world",
+	"name":: joe,
+	'mood'::: "happy",
+	|||
+	  key type
+|||: "block",
+}`,
+
+	`assert true: 'woah!'; true`,
+	`{ assert true: 'woah!', foo: bar }`,
+
+	`if n > 1 then 'foos' else 'foo'`,
+
+	`local foo = function(x) x + 1; true`,
+
+	`import 'foo.jsonnet'`,
+	`importstr 'foo.text'`,
+
+	`{a: b} + {c: d}`,
+	`{a: b}{c: d}`,
+}
 
 func TestParser(t *testing.T) {
-	tokens, err := lex("test", `{hello: "world"}`)
-	if err != nil {
-		t.Errorf("Unexpected lex error: %v", err)
+	for _, s := range tests {
+		tokens, err := lex("test", s)
+		if err != nil {
+			t.Errorf("Unexpected lex error\n  input: %v\n  error: %v", s, err)
+			continue
+		}
+		_, err = parse(tokens)
+		if err != nil {
+			t.Errorf("Unexpected parse error\n  input: %v\n  error: %v", s, err)
+		}
 	}
-	ast, err := parse(tokens)
-	if err != nil {
-		t.Errorf("Unexpected parse error: %v", err)
+}
+
+type testError struct {
+	input string
+	err   string
+}
+
+var errorTests = []testError{
+	{`function(a, b c)`, `test:1:15-16 Expected a comma before next function parameter.`},
+	{`function(a, 1)`, `test:1:13-14 Expected simple identifier but got a complex expression.`},
+	{`a b`, `test:1:3-4 Did not expect: (IDENTIFIER, "b")`},
+	{`foo(a, bar(a b))`, `test:1:14-15 Expected a comma before next function argument.`},
+
+	{`local`, `test:1:6 Expected token IDENTIFIER but got end of file`},
+	{`local foo = 1, foo = 2; true`, `test:1:16-19 Duplicate local var: foo`},
+	{`local foo(a b) = a; true`, `test:1:13-14 Expected a comma before next function parameter.`},
+	{`local foo(a): a; true`, `test:1:13-14 Expected operator = but got ":"`},
+	{`local foo(a) = bar(a b); true`, `test:1:22-23 Expected a comma before next function argument.`},
+	{`local foo: 1; true`, `test:1:10-11 Expected operator = but got ":"`},
+	{`local foo = bar(a b); true`, `test:1:19-20 Expected a comma before next function argument.`},
+
+	{`{a b}`, `test:1:4-5 Expected token OPERATOR but got (IDENTIFIER, "b")`},
+	{`{a = b}`, `test:1:4-5 Expected one of :, ::, :::, +:, +::, +:::, got: =`},
+	{`{a :::: b}`, `test:1:4-8 Expected one of :, ::, :::, +:, +::, +:::, got: ::::`},
+
+	{`{assert x for x in [1, 2, 3]}`, `test:1:11-14 Object comprehension cannot have asserts.`},
+	{`{['foo' + x]: true, [x]: x for x in [1, 2, 3]}`, `test:1:28-31 Object comprehension can only have one field.`},
+	{`{foo: x for x in [1, 2, 3]}`, `test:1:9-12 Object comprehensions can only have [e] fields.`},
+	{`{[x]:: true for x in [1, 2, 3]}`, `test:1:13-16 Object comprehensions cannot have hidden fields.`},
+	{`{[x]: true for 1 in [1, 2, 3]}`, `test:1:16-17 Expected token IDENTIFIER but got (NUMBER, "1")`},
+	{`{[x]: true for x at [1, 2, 3]}`, `test:1:18-20 Expected token in but got (IDENTIFIER, "at")`},
+	{`{[x]: true for x in [1, 2 3]}`, `test:1:27-28 Expected a comma before next array element.`},
+	{`{[x]: true for x in [1, 2, 3] if (a b)}`, `test:1:37-38 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`{[x]: true for x in [1, 2, 3] if a b}`, `test:1:36-37 Expected for, if or "}" after for clause, got: (IDENTIFIER, "b")`},
+
+	{`{a: b c:d}`, `test:1:7-8 Expected a comma before next field.`},
+
+	{`{[(x y)]: z}`, `test:1:6-7 Expected token ")" but got (IDENTIFIER, "y")`},
+	{`{[x y]: z}`, `test:1:5-6 Expected token "]" but got (IDENTIFIER, "y")`},
+
+	{`{foo(x y): z}`, `test:1:8-9 Expected a comma before next method parameter.`},
+	{`{foo(x)+: z}`, `test:1:2-5 Cannot use +: syntax sugar in a method: foo`},
+	{`{foo: 1, foo: 2}`, `test:1:10-13 Duplicate field: foo`},
+	{`{foo: (1 2)}`, `test:1:10-11 Expected token ")" but got (NUMBER, "2")`},
+
+	{`{local 1 = 3, true}`, `test:1:8-9 Expected token IDENTIFIER but got (NUMBER, "1")`},
+	{`{local foo = 1, local foo = 2, true}`, `test:1:23-26 Duplicate local var: foo`},
+	{`{local foo(a b) = 1, a: true}`, `test:1:14-15 Expected a comma before next function parameter.`},
+	{`{local foo(a): 1, a: true}`, `test:1:14-15 Expected operator = but got ":"`},
+	{`{local foo(a) = (a b), a: true}`, `test:1:20-21 Expected token ")" but got (IDENTIFIER, "b")`},
+
+	{`{assert (a b), a: true}`, `test:1:12-13 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`{assert a: (a b), a: true}`, `test:1:15-16 Expected token ")" but got (IDENTIFIER, "b")`},
+
+	{`{function(a, b) a+b: true}`, `test:1:2-10 Unexpected: (function, "function") while parsing field definition`},
+
+	{`[(a b), 2, 3]`, `test:1:5-6 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`[1, (a b), 2, 3]`, `test:1:8-9 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`[a for b in [1 2 3]]`, `test:1:16-17 Expected a comma before next array element.`},
+
+	{`for`, `test:1:1-4 Unexpected: (for, "for") while parsing terminal`},
+	{``, `test:1:1 Unexpected end of file.`},
+	{`((a b))`, `test:1:5-6 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`a.1`, `test:1:3-4 Expected token IDENTIFIER but got (NUMBER, "1")`},
+	{`super.1`, `test:1:7-8 Expected token IDENTIFIER but got (NUMBER, "1")`},
+	{`super[(a b)]`, `test:1:10-11 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`super[a b]`, `test:1:9-10 Expected token "]" but got (IDENTIFIER, "b")`},
+	{`super`, `test:1:1-6 Expected . or [ after super.`},
+
+	{`assert (a b); true`, `test:1:11-12 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`assert a: (a b); true`, `test:1:14-15 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`assert a: 'foo', true`, `test:1:16-17 Expected token ";" but got (",", ",")`},
+	{`assert a: 'foo'; (a b)`, `test:1:21-22 Expected token ")" but got (IDENTIFIER, "b")`},
+
+	{`error (a b)`, `test:1:10-11 Expected token ")" but got (IDENTIFIER, "b")`},
+
+	{`if (a b) then c`, `test:1:7-8 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`if a b c`, `test:1:6-7 Expected token then but got (IDENTIFIER, "b")`},
+	{`if a then (b c)`, `test:1:14-15 Expected token ")" but got (IDENTIFIER, "c")`},
+	{`if a then b else (c d)`, `test:1:21-22 Expected token ")" but got (IDENTIFIER, "d")`},
+
+	{`function(a) (a b)`, `test:1:16-17 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`function a a`, `test:1:10-11 Expected ( but got (IDENTIFIER, "a")`},
+
+	{`import (a b)`, `test:1:11-12 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`import (a+b)`, `test:1:9-12 Computed imports are not allowed`},
+	{`importstr (a b)`, `test:1:14-15 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`importstr (a+b)`, `test:1:12-15 Computed imports are not allowed`},
+
+	{`local a = b ()`, `test:1:15 Expected , or ; but got end of file`},
+	{`local a = b; (a b)`, `test:1:17-18 Expected token ")" but got (IDENTIFIER, "b")`},
+
+	{`1+ <<`, `test:1:4-6 Not a unary operator: <<`},
+	{`-(a b)`, `test:1:5-6 Expected token ")" but got (IDENTIFIER, "b")`},
+	{`1~2`, `test:1:2-3 Not a binary operator: ~`},
+
+	{`a[(b c)]`, `test:1:6-7 Expected token ")" but got (IDENTIFIER, "c")`},
+	{`a[b c]`, `test:1:5-6 Expected token "]" but got (IDENTIFIER, "c")`},
+
+	{`a{b c}`, `test:1:5-6 Expected token OPERATOR but got (IDENTIFIER, "c")`},
+}
+
+func TestParserErrors(t *testing.T) {
+	for _, s := range errorTests {
+		tokens, err := lex("test", s.input)
+		if err != nil {
+			t.Errorf("Unexpected lex error\n  input: %v\n  error: %v", s.input, err)
+			continue
+		}
+		_, err = parse(tokens)
+		if err == nil {
+			t.Errorf("Expected parse error but got success\n  input: %v", s.input)
+			continue
+		}
+		if err.Error() != s.err {
+			t.Errorf("Error string not as expected\n  input: %v\n  expected error: %v\n  actual error: %v", s.input, s.err, err.Error())
+		}
 	}
-	fmt.Printf("%# v", pretty.Formatter(ast))
+
 }