com.google.javascript.jscomp.AstValidator Maven / Gradle / Ivy
/*
* Copyright 2011 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Strings.isNullOrEmpty;
import com.google.common.collect.ImmutableSet;
import com.google.javascript.jscomp.parsing.parser.FeatureSet;
import com.google.javascript.jscomp.parsing.parser.FeatureSet.Feature;
import com.google.javascript.rhino.InputId;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import com.google.javascript.rhino.jstype.FunctionType;
import com.google.javascript.rhino.jstype.JSType;
import com.google.javascript.rhino.jstype.JSType.Nullability;
import java.util.Objects;
import javax.annotation.Nullable;
/**
* This class walks the AST and validates that the structure is correct.
*/
public final class AstValidator implements CompilerPass {
// Possible enhancements:
// * verify NAME, LABEL_NAME, GETPROP property name and unquoted
// object-literal keys are valid JavaScript identifiers.
// * optionally verify every node has source location information.
/** Violation handler */
public interface ViolationHandler {
void handleViolation(String message, Node n);
}
private final AbstractCompiler compiler;
private final ViolationHandler violationHandler;
private Node currentScript;
/** Perform type validation if this is enabled. */
private boolean isTypeValidationEnabled = false;
/** Validate that a SCRIPT's FeatureSet property includes all features if this is enabled. */
private final boolean isScriptFeatureValidationEnabled;
public AstValidator(
AbstractCompiler compiler, ViolationHandler handler, boolean validateScriptFeatures) {
this.compiler = compiler;
this.violationHandler = handler;
this.isScriptFeatureValidationEnabled = validateScriptFeatures;
}
/**
* Deprecated - use the three-argument constructor instead to specify validateScriptFeatures.
* TODO(lharker): remove this constructor after the next external release.
*/
@Deprecated
public AstValidator(AbstractCompiler compiler, ViolationHandler handler) {
this(compiler, handler, false);
}
public AstValidator(AbstractCompiler compiler) {
this(compiler, /* validateScriptFeatures= */ false);
}
public AstValidator(AbstractCompiler compiler, boolean validateScriptFeatures) {
this(
compiler,
new ViolationHandler() {
@Override
public void handleViolation(String message, Node n) {
throw new IllegalStateException(
message
+ ". Reference node:\n"
+ n.toStringTree()
+ "\n Parent node:\n"
+ ((n.getParent() != null) ? n.getParent().toStringTree() : " no parent "));
}
},
validateScriptFeatures);
}
/**
* Enable or disable validation of type information.
*
* TODO(b/74537281): Currently only expressions are checked for type information.
* Do we need to do more?
*/
public AstValidator setTypeValidationEnabled(boolean isEnabled) {
isTypeValidationEnabled = isEnabled;
return this;
}
@Override
public void process(Node externs, Node root) {
if (externs != null) {
validateCodeRoot(externs);
}
if (root != null) {
validateCodeRoot(root);
}
}
public void validateRoot(Node n) {
validateNodeType(Token.ROOT, n);
validateChildCount(n, 2);
validateCodeRoot(n.getFirstChild());
validateCodeRoot(n.getLastChild());
}
public void validateCodeRoot(Node n) {
validateNodeType(Token.ROOT, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateScript(c);
}
}
public void validateScript(Node n) {
validateNodeType(Token.SCRIPT, n);
validateHasSourceName(n);
validateHasInputId(n);
currentScript = n;
if (n.hasChildren() && n.getFirstChild().isModuleBody()) {
validateChildCount(n, 1);
validateModuleContents(n.getFirstChild());
} else {
validateStatements(n.getFirstChild());
}
}
public void validateModuleContents(Node n) {
validateNodeType(Token.MODULE_BODY, n);
validateStatements(n.getFirstChild());
}
public void validateStatements(Node n) {
while (n != null) {
validateStatement(n);
n = n.getNext();
}
}
public void validateStatement(Node n) {
validateStatement(n, false);
}
public void validateStatement(Node n, boolean isAmbient) {
switch (n.getToken()) {
case LABEL:
validateLabel(n);
return;
case BLOCK:
validateBlock(n);
return;
case FUNCTION:
if (isAmbient) {
validateFunctionSignature(n);
} else {
validateFunctionStatement(n);
}
return;
case WITH:
validateWith(n);
return;
case FOR:
validateFor(n);
return;
case FOR_IN:
validateForIn(n);
return;
case FOR_OF:
validateForOf(n);
return;
case FOR_AWAIT_OF:
validateForAwaitOf(n);
return;
case WHILE:
validateWhile(n);
return;
case DO:
validateDo(n);
return;
case SWITCH:
validateSwitch(n);
return;
case IF:
validateIf(n);
return;
case CONST:
for (Node child : n.children()) {
if (child.isDestructuringLhs()) {
// Must have two children: First child of the DESTRUCTURING_LHS node is the pattern on
// the LHS, second is the RHS.
validateChildCount(child, 2);
} else {
// Must have a child, which is the RHS (unlike VAR and LET which may have no RHS).
validateChildCount(child, 1);
}
}
// fallthrough
case VAR:
case LET:
validateNameDeclarationHelper(n.getToken(), n);
return;
case EXPR_RESULT:
validateExprStmt(n);
return;
case RETURN:
validateReturn(n);
return;
case THROW:
validateThrow(n);
return;
case TRY:
validateTry(n);
return;
case BREAK:
validateBreak(n);
return;
case CONTINUE:
validateContinue(n);
return;
case EMPTY:
case DEBUGGER:
validateChildless(n);
return;
case CLASS:
validateClassDeclaration(n, isAmbient);
return;
case IMPORT:
validateImport(n);
return;
case EXPORT:
validateExport(n, isAmbient);
return;
case INTERFACE:
validateInterface(n);
return;
case ENUM:
validateEnum(n);
return;
case TYPE_ALIAS:
validateTypeAlias(n);
return;
case DECLARE:
validateAmbientDeclaration(n);
return;
case NAMESPACE:
validateNamespace(n, isAmbient);
return;
default:
violation("Expected statement but was " + n.getToken() + ".", n);
}
}
public void validateExpression(Node n) {
if (isTypeValidationEnabled) {
validateExpressionType(n);
}
switch (n.getToken()) {
// Childless expressions
case NEW_TARGET:
validateFeature(Feature.NEW_TARGET, n);
validateChildless(n);
return;
case IMPORT_META:
validateFeature(Feature.IMPORT_META, n);
validateChildless(n);
return;
case SUPER:
validateFeature(Feature.SUPER, n);
validateChildless(n);
return;
case FALSE:
case NULL:
case THIS:
case TRUE:
validateChildless(n);
return;
// General unary ops
case DELPROP:
case POS:
case NEG:
case NOT:
case TYPEOF:
case VOID:
case BITNOT:
case CAST:
validateUnaryOp(n);
return;
case INC:
case DEC:
validateIncDecOp(n);
return;
// Assignments
case ASSIGN:
validateAssignmentExpression(n);
return;
case ASSIGN_EXPONENT:
validateFeature(Feature.EXPONENT_OP, n);
validateCompoundAssignmentExpression(n);
return;
case ASSIGN_BITOR:
case ASSIGN_BITXOR:
case ASSIGN_BITAND:
case ASSIGN_LSH:
case ASSIGN_RSH:
case ASSIGN_URSH:
case ASSIGN_ADD:
case ASSIGN_SUB:
case ASSIGN_MUL:
case ASSIGN_DIV:
case ASSIGN_MOD:
validateCompoundAssignmentExpression(n);
return;
case HOOK:
validateTrinaryOp(n);
return;
// Node types that require special handling
case STRING:
validateString(n);
return;
case NUMBER:
validateNumber(n);
return;
case NAME:
validateName(n);
return;
// General binary ops
case EXPONENT:
validateFeature(Feature.EXPONENT_OP, n);
validateBinaryOp(n);
return;
case GETELEM:
case COMMA:
case OR:
case AND:
case BITOR:
case BITXOR:
case BITAND:
case EQ:
case NE:
case SHEQ:
case SHNE:
case LT:
case GT:
case LE:
case GE:
case INSTANCEOF:
case IN:
case LSH:
case RSH:
case URSH:
case SUB:
case ADD:
case MUL:
case MOD:
case DIV:
validateBinaryOp(n);
return;
case GETPROP:
validateGetProp(n);
return;
case ARRAYLIT:
validateArrayLit(n);
return;
case OBJECTLIT:
validateObjectLit(n);
return;
case REGEXP:
validateRegExpLit(n);
return;
case CALL:
validateCall(n);
return;
case NEW:
validateNew(n);
return;
case FUNCTION:
validateFunctionExpression(n);
return;
case CLASS:
validateClass(n);
return;
case TEMPLATELIT:
validateTemplateLit(n);
return;
case TAGGED_TEMPLATELIT:
validateTaggedTemplateLit(n);
return;
case YIELD:
validateYield(n);
return;
case AWAIT:
validateAwait(n);
return;
default:
violation("Expected expression but was " + n.getToken(), n);
}
}
/**
* Validate an expression or expresison-like construct.
*
* An expression-like construct (pseudoexpression) is an AST fragment that is valid in some,
* but not all, of the same contexts as true expressions. For example, a VANILLA_FOR permits EMPTY
* as its condition and increment expressions, even though EMPTY is not valid as an expression in
* general.
*
*
{@code allowedPseudoexpressions} allows the caller to specify which pseudoexpressions are
* valid for their context. If {@code n} is a pseudoexpression, it will be considered invalid
* unless its token is in this set.
*/
private void validatePseudoExpression(Node n, Token... allowedPseudoexpressions) {
switch (n.getToken()) {
case EMPTY:
validateChildless(n);
break;
case ITER_SPREAD:
validateChildCount(n);
validateFeature(Feature.SPREAD_EXPRESSIONS, n);
validateExpression(n.getFirstChild());
break;
default:
validateExpression(n);
return;
}
// This also implicitly validates that only known expression and pseudo-expression tokens are
// permitted.
ImmutableSet set = ImmutableSet.copyOf(allowedPseudoexpressions);
if (!set.contains(n.getToken())) {
violation("Expected expression or " + set + " but was " + n.getToken(), n);
}
}
private void validateExpressionType(Node n) {
switch (n.getToken()) {
case NAME:
validateNameType(n);
break;
case CALL:
if (!n.getFirstChild().isSuper()) {
// TODO(sdh): need to validate super() using validateNewType() instead, if it existed
validateCallType(n);
}
break;
default:
expectSomeTypeInformation(n);
}
}
private void validateNameType(Node nameNode) {
// TODO(bradfordcsmith): Looking at ancestors of nameNode is a hack that will prevent validation
// from working on detached nodes.
// Calling code should correctly determine the context and call different methods as
// appropriate.
if (NodeUtil.isExpressionResultUsed(nameNode) && !NodeUtil.isGet(nameNode.getParent())) {
// If the expression result is used, it must have a type.
// However, we don't always add a type when the name is just part of a getProp or getElem.
// That's OK, because we'll do type checking on the getProp/Elm itself, which has a type.
// TODO(b/74537281): Why do we sometimes have type information for names used in getprop
// or getelem expressions and sometimes not?
expectSomeTypeInformation(nameNode);
}
}
private void validateCallType(Node callNode) {
// TODO(b/74537281): Shouldn't CALL nodes always have a type, even if it is unknown?
Node callee = callNode.getFirstChild();
JSType calleeType =
checkNotNull(callee.getJSType(), "Callee of\n\n%s\nhas no type.", callNode.toStringTree());
if (calleeType.isFunctionType()) {
FunctionType calleeFunctionType = calleeType.toMaybeFunctionType();
JSType returnType = calleeFunctionType.getReturnType();
// Skip this check if the call node was originally in a cast, because the cast type may be
// narrower than the return type. Also skip the check if the function's return type is the
// any (formerly unknown) type, since we may have inferred a better type.
if (callNode.getJSTypeBeforeCast() == null && !returnType.isUnknownType()) {
expectMatchingTypeInformation(callNode, returnType);
}
} // TODO(b/74537281): What other cases should be covered?
}
private void expectSomeTypeInformation(Node n) {
if (n.getJSType() == null) {
violation(
"Type information missing" + "\n" + compiler.toSource(NodeUtil.getEnclosingStatement(n)),
n);
}
}
private void expectMatchingTypeInformation(Node n, JSType expectedTypeI) {
JSType typeI = n.getJSType();
if (!Objects.equals(expectedTypeI, typeI)) {
violation(
"Expected type: "
+ getTypeAnnotationString(expectedTypeI)
+ " Actual type: "
+ getTypeAnnotationString(typeI),
n);
}
}
private String getTypeAnnotationString(@Nullable JSType typeI) {
if (typeI == null) {
return "NO TYPE INFORMATION";
} else {
return "{" + typeI.toAnnotationString(Nullability.EXPLICIT) + "}";
}
}
private void validateYield(Node n) {
validateFeature(Feature.GENERATORS, n);
validateNodeType(Token.YIELD, n);
validateChildCountIn(n, 0, 1);
if (n.hasChildren()) {
validateExpression(n.getFirstChild());
}
}
private void validateAwait(Node n) {
validateFeature(Feature.ASYNC_FUNCTIONS, n);
validateNodeType(Token.AWAIT, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateWithinAsyncFunction(n);
}
private void validateWithinAsyncFunction(Node n) {
Node parentFunction = NodeUtil.getEnclosingFunction(n);
if (parentFunction == null || !parentFunction.isAsyncFunction()) {
violation("'await' expression is not within an async function", n);
}
}
private void validateImport(Node n) {
validateFeature(Feature.MODULES, n);
validateNodeType(Token.IMPORT, n);
validateChildCount(n);
if (n.getFirstChild().isName()) {
validateName(n.getFirstChild());
} else {
validateNodeType(Token.EMPTY, n.getFirstChild());
}
Node secondChild = n.getSecondChild();
switch (secondChild.getToken()) {
case IMPORT_SPECS:
validateImportSpecifiers(secondChild);
break;
case IMPORT_STAR:
validateNonEmptyString(secondChild);
break;
default:
validateNodeType(Token.EMPTY, secondChild);
}
validateString(n.getChildAtIndex(2));
}
private void validateImportSpecifiers(Node n) {
validateNodeType(Token.IMPORT_SPECS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateImportSpecifier(c);
}
}
private void validateImportSpecifier(Node n) {
validateNodeType(Token.IMPORT_SPEC, n);
validateChildCount(n, 2);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateName(c);
}
}
private void validateExport(Node n, boolean isAmbient) {
validateFeature(Feature.MODULES, n);
validateNodeType(Token.EXPORT, n);
if (n.getBooleanProp(Node.EXPORT_ALL_FROM)) { // export * from "mod"
validateChildCount(n, 2);
validateNodeType(Token.EMPTY, n.getFirstChild());
validateString(n.getSecondChild());
} else if (n.getBooleanProp(Node.EXPORT_DEFAULT)) { // export default foo = 2
validateChildCount(n, 1);
validateExpression(n.getFirstChild());
} else {
validateChildCountIn(n, 1, 2);
if (n.getFirstChild().getToken() == Token.EXPORT_SPECS) {
validateExportSpecifiers(n.getFirstChild());
} else {
validateStatement(n.getFirstChild(), isAmbient);
}
if (n.hasTwoChildren()) {
validateString(n.getSecondChild());
}
}
}
private void validateExportSpecifiers(Node n) {
validateNodeType(Token.EXPORT_SPECS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateExportSpecifier(c);
}
}
private void validateExportSpecifier(Node n) {
validateNodeType(Token.EXPORT_SPEC, n);
validateChildCount(n, 2);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateName(c);
}
}
private void validateTaggedTemplateLit(Node n) {
validateFeature(Feature.TEMPLATE_LITERALS, n);
validateNodeType(Token.TAGGED_TEMPLATELIT, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateTemplateLit(n.getLastChild());
}
private void validateTemplateLit(Node n) {
validateFeature(Feature.TEMPLATE_LITERALS, n);
validateNodeType(Token.TEMPLATELIT, n);
for (Node child = n.getFirstChild(); child != null; child = child.getNext()) {
if (child.isTemplateLitString()) {
validateTemplateLitString(child);
} else {
validateTemplateLitSub(child);
}
}
}
private void validateTemplateLitString(Node n) {
validateNodeType(Token.TEMPLATELIT_STRING, n);
validateChildCount(n);
try {
// Validate that getRawString doesn't throw
n.getRawString();
} catch (UnsupportedOperationException e) {
violation("Invalid TEMPLATELIT_STRING node.", n);
}
}
private void validateTemplateLitSub(Node n) {
validateNodeType(Token.TEMPLATELIT_SUB, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
}
private void validateInterface(Node n) {
validateFeature(Feature.INTERFACE, n);
validateNodeType(Token.INTERFACE, n);
validateChildCount(n);
Node name = n.getFirstChild();
validateName(name);
Node superTypes = name.getNext();
if (superTypes.isEmpty()) {
validateChildless(superTypes);
} else {
validateInterfaceExtends(superTypes);
}
validateInterfaceMembers(n.getLastChild());
}
private void validateInterfaceExtends(Node n) {
validateNodeType(Token.INTERFACE_EXTENDS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateNamedType(c);
}
}
private void validateInterfaceMembers(Node n) {
validateNodeType(Token.INTERFACE_MEMBERS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateInterfaceMember(c);
}
}
private void validateInterfaceMember(Node n) {
switch (n.getToken()) {
case MEMBER_FUNCTION_DEF:
validateChildCount(n);
validateFunctionSignature(n.getFirstChild());
break;
case MEMBER_VARIABLE_DEF:
validateChildless(n);
break;
case INDEX_SIGNATURE:
validateChildCount(n);
validateChildless(n.getFirstChild());
break;
case CALL_SIGNATURE:
validateChildCount(n);
break;
default:
violation("Interface contained member of invalid type " + n.getToken(), n);
}
}
private void validateEnum(Node n) {
validateNodeType(Token.ENUM, n);
validateName(n.getFirstChild());
validateEnumMembers(n.getLastChild());
}
private void validateEnumMembers(Node n) {
validateNodeType(Token.ENUM_MEMBERS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateEnumStringKey(c);
}
}
private void validateEnumStringKey(Node n) {
validateNodeType(Token.STRING_KEY, n);
validateObjectLiteralKeyName(n);
validateChildCount(n, 0);
}
/**
* In a class declaration, unlike a class expression,
* the class name is required.
*/
private void validateClassDeclaration(Node n, boolean isAmbient) {
validateClassHelper(n, isAmbient);
validateName(n.getFirstChild());
}
private void validateClass(Node n) {
validateClassHelper(n, false);
}
private void validateClassHelper(Node n, boolean isAmbient) {
validateFeature(Feature.CLASSES, n);
validateNodeType(Token.CLASS, n);
validateChildCount(n);
Node name = n.getFirstChild();
if (name.isEmpty()) {
validateChildless(name);
} else {
validateName(name);
}
Node superClass = name.getNext();
if (superClass.isEmpty()) {
validateChildless(superClass);
} else {
validateFeature(Feature.CLASS_EXTENDS, n);
validateExpression(superClass);
}
validateClassMembers(n.getLastChild(), isAmbient);
}
private void validateClassMembers(Node n, boolean isAmbient) {
validateNodeType(Token.CLASS_MEMBERS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateClassMember(c, isAmbient);
}
}
private void validateClassMember(Node n, boolean isAmbient) {
switch (n.getToken()) {
case MEMBER_FUNCTION_DEF:
validateFeature(Feature.MEMBER_DECLARATIONS, n);
validateObjectLiteralKeyName(n);
validateChildCount(n);
validateMemberFunction(n, isAmbient);
break;
case GETTER_DEF:
case SETTER_DEF:
validateFeature(Feature.CLASS_GETTER_SETTER, n);
validateObjectLiteralKeyName(n);
validateObjectLitKey(n);
validateChildCount(n);
validateMemberFunction(n, isAmbient);
break;
case MEMBER_VARIABLE_DEF:
validateChildless(n);
break;
case COMPUTED_PROP:
validateComputedPropClassMethod(n);
break;
case INDEX_SIGNATURE:
validateChildCount(n);
validateChildless(n.getFirstChild());
break;
case CALL_SIGNATURE:
validateChildCount(n);
break;
case EMPTY: // Empty is allowed too.
break;
default:
violation("Class contained member of invalid type " + n.getToken(), n);
}
}
private void validateMemberFunction(Node n, boolean isAmbient) {
Node function = n.getFirstChild();
if (isAmbient) {
validateFunctionSignature(function);
} else {
validateFunctionExpression(function);
}
}
private void validateBlock(Node n) {
validateNodeType(Token.BLOCK, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateStatement(c);
}
}
private void validateHasSourceName(Node n) {
String sourceName = n.getSourceFileName();
if (isNullOrEmpty(sourceName)) {
violation("Missing 'source name' annotation.", n);
}
}
private void validateHasInputId(Node n) {
InputId inputId = n.getInputId();
if (inputId == null) {
violation("Missing 'input id' annotation.", n);
}
}
private void validateLabel(Node n) {
validateNodeType(Token.LABEL, n);
validateChildCount(n);
validateLabelName(n.getFirstChild());
validateStatement(n.getLastChild());
}
private void validateLabelName(Node n) {
validateNodeType(Token.LABEL_NAME, n);
validateNonEmptyString(n);
validateChildCount(n);
}
private void validateNonEmptyString(Node n) {
if (validateNonNullString(n) && n.getString().isEmpty()) {
violation("Expected non-empty string.", n);
}
}
private void validateEmptyString(Node n) {
if (validateNonNullString(n) && !n.getString().isEmpty()) {
violation("Expected empty string.", n);
}
}
private boolean validateNonNullString(Node n) {
try {
if (n.getString() == null) {
violation("Expected non-null string.", n);
return false;
}
} catch (Exception e) {
violation("Expected non-null string.", n);
return false;
}
return true;
}
private void validateName(Node n) {
validateNodeType(Token.NAME, n);
validateNonEmptyString(n);
validateChildCount(n);
}
private void validateOptionalName(Node n) {
validateNodeType(Token.NAME, n);
validateNonNullString(n);
validateChildCount(n);
}
private void validateEmptyName(Node n) {
validateNodeType(Token.NAME, n);
validateEmptyString(n);
validateChildCount(n);
}
private void validateFunctionStatement(Node n) {
validateNodeType(Token.FUNCTION, n);
validateChildCount(n);
validateName(n.getFirstChild());
validateParameters(n.getSecondChild());
validateFunctionBody(n.getLastChild(), false);
validateFunctionFeatures(n);
if (n.getParent().isBlock() && !n.getGrandparent().isFunction()) {
// e.g. if (true) { function f() {} }
validateFeature(Feature.BLOCK_SCOPED_FUNCTION_DECLARATION, n);
}
}
private void validateFunctionExpression(Node n) {
validateFunctionExpressionHelper(n, false);
}
private void validateFunctionSignature(Node n) {
validateFunctionExpressionHelper(n, true);
}
private void validateFunctionExpressionHelper(Node n, boolean isAmbient) {
validateNodeType(Token.FUNCTION, n);
validateChildCount(n);
validateParameters(n.getSecondChild());
Node name = n.getFirstChild();
Node body = n.getLastChild();
if (n.isArrowFunction()) {
validateEmptyName(name);
if (body.isBlock()) {
validateBlock(body);
} else {
validateExpression(body);
}
} else {
validateOptionalName(name);
validateFunctionBody(body, isAmbient);
}
validateFunctionFeatures(n);
}
private void validateFunctionFeatures(Node n) {
if (n.isArrowFunction()) {
validateFeature(Feature.ARROW_FUNCTIONS, n);
}
if (n.isGeneratorFunction()) {
validateFeature(Feature.GENERATORS, n);
}
if (n.isAsyncFunction()) {
validateFeature(Feature.ASYNC_FUNCTIONS, n);
}
if (n.isAsyncFunction() && n.isGeneratorFunction()) {
validateFeature(Feature.ASYNC_GENERATORS, n);
}
}
private void validateFunctionBody(Node n, boolean noBlock) {
if (noBlock) {
validateNodeType(Token.EMPTY, n);
} else {
validateBlock(n);
}
}
private void validateParameters(Node n) {
validateNodeType(Token.PARAM_LIST, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
if (c.isRest()) {
validateRestParameters(Token.PARAM_LIST, c);
} else if (c.isDefaultValue()) {
validateFeature(Feature.DEFAULT_PARAMETERS, c);
validateDefaultValue(Token.PARAM_LIST, c);
} else {
if (c.isName()) {
validateName(c);
} else if (c.isArrayPattern()) {
validateArrayPattern(Token.PARAM_LIST, c);
} else {
validateObjectPattern(Token.PARAM_LIST, c);
}
}
}
}
private void validateDefaultValue(Token contextType, Node n) {
validateChildCount(n);
validateLHS(contextType, n.getFirstChild());
validateExpression(n.getLastChild());
}
private void validateCall(Node n) {
validateNodeType(Token.CALL, n);
validateMinimumChildCount(n, 1);
validateExpression(n.getFirstChild());
for (Node c = n.getSecondChild(); c != null; c = c.getNext()) {
validatePseudoExpression(c, Token.ITER_SPREAD);
}
}
private void validateRestParameters(Token contextType, Node n) {
validateFeature(Feature.REST_PARAMETERS, n);
validateRest(contextType, n);
}
private void validateArrayPatternRest(Token contextType, Node n) {
validateFeature(Feature.ARRAY_PATTERN_REST, n);
validateRest(contextType, n);
}
private void validateObjectPatternRest(Token contextType, Node n) {
validateFeature(Feature.OBJECT_PATTERN_REST, n);
validateRest(contextType, n);
}
/**
* @param contextType A {@link Token} constant value indicating that {@code n} should be validated
* appropriately for a descendant of a {@link Node} of this type.
* @param n
*/
private void validateRest(Token contextType, Node n) {
switch (n.getToken()) {
case ITER_REST:
case OBJECT_REST:
break;
default:
violation("Unexpected node type.", n);
return;
}
validateChildCount(n);
validateLHS(contextType, n.getFirstChild());
if (n.getNext() != null) {
violation("Rest parameters must come after all other parameters.", n);
}
}
private void validateObjectSpread(Node n) {
validateChildCount(n);
validateFeature(Feature.OBJECT_LITERALS_WITH_SPREAD, n);
validateExpression(n.getFirstChild());
}
private void validateNew(Node n) {
validateNodeType(Token.NEW, n);
validateMinimumChildCount(n, 1);
validateExpression(n.getFirstChild());
for (Node c = n.getSecondChild(); c != null; c = c.getNext()) {
validatePseudoExpression(c, Token.ITER_SPREAD);
}
}
private void validateNameDeclarationHelper(Token type, Node n) {
validateMinimumChildCount(n, 1);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateNameDeclarationChild(type, c);
}
if (type == Token.LET) {
validateFeature(Feature.LET_DECLARATIONS, n);
} else if (type == Token.CONST) {
validateFeature(Feature.CONST_DECLARATIONS, n);
}
}
private void validateNameDeclarationChild(Token type, Node n) {
if (n.isName()) {
// Don't use validateName here since this NAME node may have
// a child.
validateNonEmptyString(n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateExpression(n.getFirstChild());
}
} else if (n.isDestructuringLhs()) {
validateDestructuringLhs(type, n);
} else {
violation("Invalid child for " + type + " node", n);
}
}
private void validateDestructuringLhs(Token type, Node n) {
validateChildCountIn(n, 1, 2);
Node c = n.getFirstChild();
switch (c.getToken()) {
case ARRAY_PATTERN:
validateArrayPattern(type, c);
break;
case OBJECT_PATTERN:
validateObjectPattern(type, c);
break;
default:
violation("Invalid destructuring lhs first child for " + type + " node", n);
}
if (n.hasTwoChildren()) {
validateExpression(n.getSecondChild());
}
}
/**
* @param contextType A {@link Token} constant value indicating that {@code n} should be validated
* appropriately for a descendant of a {@link Node} of this type.
* @param n
*/
private void validateLHS(Token contextType, Node n) {
switch (n.getToken()) {
case NAME:
validateName(n);
break;
case ARRAY_PATTERN:
validateArrayPattern(contextType, n);
break;
case OBJECT_PATTERN:
validateObjectPattern(contextType, n);
break;
case GETPROP:
case GETELEM:
validateGetPropGetElemInLHS(contextType, n);
break;
case CAST:
validateLHS(contextType, n.getOnlyChild());
break;
default:
violation("Invalid child for " + contextType + " node", n);
}
}
private void validateGetPropGetElemInLHS(Token contextType, Node n) {
if (contextType == Token.CONST || contextType == Token.LET || contextType == Token.VAR
|| contextType == Token.PARAM_LIST) {
violation("Invalid child for " + contextType + " node", n);
return;
}
switch (n.getToken()) {
case GETPROP:
validateGetProp(n);
break;
case GETELEM:
validateBinaryOp(n);
break;
default:
throw new IllegalStateException(
"Expected GETPROP or GETELEM but instead got node " + n.getToken());
}
}
private void validateArrayPattern(Token type, Node n) {
validateFeature(Feature.ARRAY_DESTRUCTURING, n);
validateNodeType(Token.ARRAY_PATTERN, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
switch (c.getToken()) {
case DEFAULT_VALUE:
validateDefaultValue(type, c);
break;
case ITER_REST:
validateArrayPatternRest(type, c);
break;
case EMPTY:
validateChildless(c);
break;
default:
validateLHS(type, c);
}
}
}
private void validateObjectPattern(Token type, Node n) {
validateFeature(Feature.OBJECT_DESTRUCTURING, n);
validateNodeType(Token.OBJECT_PATTERN, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
switch (c.getToken()) {
case STRING_KEY:
validateObjectPatternStringKey(type, c);
break;
case OBJECT_REST:
validateObjectPatternRest(type, c);
break;
case COMPUTED_PROP:
validateObjectPatternComputedPropKey(type, c);
break;
default:
violation("Invalid object pattern child for " + type + " node", n);
}
}
}
private void validateFor(Node n) {
validateNodeType(Token.FOR, n);
validateChildCount(n, 4);
validateVarOrOptionalExpression(n.getFirstChild());
validatePseudoExpression(n.getSecondChild(), Token.EMPTY);
validatePseudoExpression(n.getChildAtIndex(2), Token.EMPTY);
validateBlock(n.getLastChild());
}
private void validateForIn(Node n) {
validateNodeType(Token.FOR_IN, n);
validateChildCount(n);
validateVarOrAssignmentTarget(n.getFirstChild());
validateExpression(n.getSecondChild());
validateBlock(n.getLastChild());
}
private void validateForOf(Node n) {
validateFeature(Feature.FOR_OF, n);
validateNodeType(Token.FOR_OF, n);
validateChildCount(n);
validateVarOrAssignmentTarget(n.getFirstChild());
validateExpression(n.getSecondChild());
validateBlock(n.getLastChild());
}
private void validateForAwaitOf(Node n) {
validateFeature(Feature.FOR_AWAIT_OF, n);
validateNodeType(Token.FOR_AWAIT_OF, n);
validateChildCount(n);
validateVarOrAssignmentTarget(n.getFirstChild());
validateExpression(n.getSecondChild());
validateBlock(n.getLastChild());
}
private void validateVarOrOptionalExpression(Node n) {
if (NodeUtil.isNameDeclaration(n)) {
validateNameDeclarationHelper(n.getToken(), n);
} else {
validatePseudoExpression(n, Token.EMPTY);
}
}
private void validateVarOrAssignmentTarget(Node n) {
if (NodeUtil.isNameDeclaration(n)) {
// Only one NAME can be declared for FOR-IN expressions.
validateChildCount(n, 1);
validateNameDeclarationHelper(n.getToken(), n);
} else {
validateLHS(n.getParent().getToken(), n);
}
}
private void validateWith(Node n) {
validateNodeType(Token.WITH, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateBlock(n.getLastChild());
}
private void validateWhile(Node n) {
validateNodeType(Token.WHILE, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateBlock(n.getLastChild());
}
private void validateDo(Node n) {
validateNodeType(Token.DO, n);
validateChildCount(n);
validateBlock(n.getFirstChild());
validateExpression(n.getLastChild());
}
private void validateIf(Node n) {
validateNodeType(Token.IF, n);
validateChildCountIn(n, 2, 3);
validateExpression(n.getFirstChild());
validateBlock(n.getSecondChild());
if (n.hasXChildren(3)) {
validateBlock(n.getLastChild());
}
}
private void validateExprStmt(Node n) {
validateNodeType(Token.EXPR_RESULT, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
}
private void validateReturn(Node n) {
validateNodeType(Token.RETURN, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateExpression(n.getFirstChild());
}
}
private void validateThrow(Node n) {
validateNodeType(Token.THROW, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
}
private void validateBreak(Node n) {
validateNodeType(Token.BREAK, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateLabelName(n.getFirstChild());
}
}
private void validateContinue(Node n) {
validateNodeType(Token.CONTINUE, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateLabelName(n.getFirstChild());
}
}
private void validateTry(Node n) {
validateNodeType(Token.TRY, n);
validateChildCountIn(n, 2, 3);
validateBlock(n.getFirstChild());
boolean seenCatchOrFinally = false;
// Validate catch
Node catches = n.getSecondChild();
validateNodeType(Token.BLOCK, catches);
validateMaximumChildCount(catches, 1);
if (catches.hasChildren()) {
validateCatch(catches.getFirstChild());
seenCatchOrFinally = true;
}
// Validate finally
if (n.hasXChildren(3)) {
validateBlock(n.getLastChild());
seenCatchOrFinally = true;
}
if (!seenCatchOrFinally) {
violation("Missing catch or finally for try statement.", n);
}
}
private void validateCatch(Node n) {
validateNodeType(Token.CATCH, n);
validateChildCount(n);
Node caught = n.getFirstChild();
if (caught.isName()) {
validateName(caught);
} else if (caught.isArrayPattern()) {
validateArrayPattern(Token.CATCH, caught);
} else if (caught.isObjectPattern()) {
validateObjectPattern(Token.CATCH, caught);
} else if (caught.isEmpty()) {
validateNoCatchBinding(caught);
} else {
violation("Unexpected catch binding: " + caught, n);
}
validateBlock(n.getLastChild());
}
private void validateNoCatchBinding(Node n) {
validateFeature(Feature.OPTIONAL_CATCH_BINDING, n);
validateChildCount(n);
}
private void validateSwitch(Node n) {
validateNodeType(Token.SWITCH, n);
validateMinimumChildCount(n, 1);
validateExpression(n.getFirstChild());
int defaults = 0;
for (Node c = n.getSecondChild(); c != null; c = c.getNext()) {
validateSwitchMember(n.getLastChild());
if (c.isDefaultCase()) {
defaults++;
}
}
if (defaults > 1) {
violation("Expected at most 1 'default' in switch but was "
+ defaults, n);
}
}
private void validateSwitchMember(Node n) {
switch (n.getToken()) {
case CASE:
validateCase(n);
return;
case DEFAULT_CASE:
validateDefaultCase(n);
return;
default:
violation("Expected switch member but was " + n.getToken(), n);
}
}
private void validateDefaultCase(Node n) {
validateNodeType(Token.DEFAULT_CASE, n);
validateChildCount(n);
validateBlock(n.getLastChild());
}
private void validateCase(Node n) {
validateNodeType(Token.CASE, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateBlock(n.getLastChild());
}
private void validateChildless(Node n) {
validateChildCount(n, 0);
}
private void validateAssignmentExpression(Node n) {
validateChildCount(n);
validateLHS(n.getToken(), n.getFirstChild());
validateExpression(n.getLastChild());
}
private void validateCompoundAssignmentExpression(Node n) {
validateChildCount(n);
Token contextType = n.getToken();
Node lhs = n.getFirstChild();
switch (lhs.getToken()) {
case NAME:
validateName(lhs);
break;
case GETPROP:
case GETELEM:
validateGetPropGetElemInLHS(contextType, lhs);
break;
default:
violation("Invalid child for " + contextType + " node", lhs);
}
validateExpression(n.getLastChild());
}
private void validateGetProp(Node n) {
validateNodeType(Token.GETPROP, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
Node prop = n.getLastChild();
validateNodeType(Token.STRING, prop);
validateNonEmptyString(prop);
}
private void validateRegExpLit(Node n) {
validateNodeType(Token.REGEXP, n);
validateChildCountIn(n, 1, 2);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateString(c);
}
}
private void validateString(Node n) {
validateNodeType(Token.STRING, n);
validateChildCount(n);
try {
// Validate that getString doesn't throw
n.getString();
} catch (UnsupportedOperationException e) {
violation("Invalid STRING node.", n);
}
}
private void validateNumber(Node n) {
validateNodeType(Token.NUMBER, n);
validateChildCount(n);
try {
// Validate that getDouble doesn't throw
n.getDouble();
} catch (UnsupportedOperationException e) {
violation("Invalid NUMBER node.", n);
}
}
private void validateArrayLit(Node n) {
validateNodeType(Token.ARRAYLIT, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
// Array-literals may have empty slots.
validatePseudoExpression(c, Token.EMPTY, Token.ITER_SPREAD);
break;
}
}
private void validateObjectLit(Node n) {
validateNodeType(Token.OBJECTLIT, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
validateObjectLitKey(c);
}
}
private void validateObjectLitKey(Node n) {
switch (n.getToken()) {
case GETTER_DEF:
validateObjectLitGetKey(n);
return;
case SETTER_DEF:
validateObjectLitSetKey(n);
return;
case STRING_KEY:
validateObjectLitStringKey(n);
return;
case MEMBER_FUNCTION_DEF:
validateClassMember(n, false);
if (n.isStaticMember()) {
violation("Keys in an object literal should not be static.", n);
}
return;
case COMPUTED_PROP:
validateObjectLitComputedPropKey(n);
return;
case OBJECT_SPREAD:
validateObjectSpread(n);
return;
default:
violation("Expected object literal key expression but was " + n.getToken(), n);
}
}
private void validateObjectLitGetKey(Node n) {
validateFeature(Feature.GETTER, n);
validateNodeType(Token.GETTER_DEF, n);
validateChildCount(n);
validateObjectLiteralKeyName(n);
Node function = n.getFirstChild();
validateFunctionExpression(function);
// objlit get functions must be nameless, and must have zero parameters.
if (!function.getFirstChild().getString().isEmpty()) {
violation("Expected unnamed function expression.", n);
}
Node functionParams = function.getSecondChild();
if (functionParams.hasChildren()) {
violation("get methods must not have parameters.", n);
}
}
private void validateObjectLitSetKey(Node n) {
validateFeature(Feature.SETTER, n);
validateNodeType(Token.SETTER_DEF, n);
validateChildCount(n);
validateObjectLiteralKeyName(n);
Node function = n.getFirstChild();
validateFunctionExpression(function);
// objlit set functions must be nameless, and must have 1 parameter.
if (!function.getFirstChild().getString().isEmpty()) {
violation("Expected unnamed function expression.", n);
}
Node functionParams = function.getSecondChild();
if (!functionParams.hasOneChild()) {
violation("set methods must have exactly one parameter.", n);
}
}
private void validateObjectLitStringKey(Node n) {
validateNodeType(Token.STRING_KEY, n);
validateObjectLiteralKeyName(n);
validateChildCount(n, 1);
validateExpression(n.getFirstChild());
if (n.getBooleanProp(Node.IS_SHORTHAND_PROPERTY)) {
validateFeature(Feature.EXTENDED_OBJECT_LITERALS, n);
}
}
private void validateObjectPatternStringKey(Token type, Node n) {
validateNodeType(Token.STRING_KEY, n);
validateObjectLiteralKeyName(n);
validateChildCount(n, 1);
Node c = n.getFirstChild();
switch (c.getToken()) {
case DEFAULT_VALUE:
validateDefaultValue(type, c);
break;
default:
validateLHS(type, c);
}
}
private void validateObjectLitComputedPropKey(Node n) {
validateFeature(Feature.COMPUTED_PROPERTIES, n);
validateNodeType(Token.COMPUTED_PROP, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
validateExpression(n.getLastChild());
}
private void validateObjectPatternComputedPropKey(Token type, Node n) {
validateFeature(Feature.COMPUTED_PROPERTIES, n);
validateNodeType(Token.COMPUTED_PROP, n);
validateChildCount(n);
validateExpression(n.getFirstChild());
if (n.getLastChild().isDefaultValue()) {
validateDefaultValue(type, n.getLastChild());
} else {
validateLHS(n.getLastChild().getToken(), n.getLastChild());
}
}
private void validateComputedPropClassMethod(Node n) {
validateFeature(Feature.COMPUTED_PROPERTIES, n);
validateNodeType(Token.COMPUTED_PROP, n);
validateExpression(n.getFirstChild());
if (n.getBooleanProp(Node.COMPUTED_PROP_VARIABLE)) {
validateChildCount(n, 1);
} else {
validateChildCount(n, 2);
validateFunctionExpression(n.getLastChild());
if (n.getBooleanProp(Node.COMPUTED_PROP_GETTER)) {
validateObjectLitComputedPropGetKey(n);
} else if (n.getBooleanProp(Node.COMPUTED_PROP_SETTER)) {
validateObjectLitComputedPropSetKey(n);
}
}
}
private void validateObjectLitComputedPropGetKey(Node n) {
validateFeature(Feature.COMPUTED_PROPERTIES, n);
validateNodeType(Token.COMPUTED_PROP, n);
validateChildCount(n);
Node function = n.getLastChild();
validateFunctionExpression(function);
// objlit get functions must be nameless, and must have zero parameters.
if (!function.getFirstChild().getString().isEmpty()) {
violation("Expected unnamed function expression.", n);
}
Node functionParams = function.getSecondChild();
if (functionParams.hasChildren()) {
violation("get methods must not have parameters.", n);
}
}
private void validateObjectLitComputedPropSetKey(Node n) {
validateFeature(Feature.COMPUTED_PROPERTIES, n);
validateNodeType(Token.COMPUTED_PROP, n);
validateChildCount(n);
Node function = n.getLastChild();
validateFunctionExpression(function);
// objlit set functions must be nameless, and must have 1 parameter.
if (!function.getFirstChild().getString().isEmpty()) {
violation("Expected unnamed function expression.", n);
}
Node functionParams = function.getSecondChild();
if (!functionParams.hasOneChild()) {
violation("set methods must have exactly one parameter.", n);
}
}
private void validateObjectLiteralKeyName(Node n) {
if (n.isQuotedString()) {
try {
// Validate that getString doesn't throw
n.getString();
} catch (UnsupportedOperationException e) {
violation("getString failed for" + n.getToken(), n);
}
} else {
validateNonEmptyString(n);
}
}
private void validateIncDecOp(Node n) {
validateChildCount(n, 1);
validateIncDecTarget(n.getFirstChild());
}
private void validateIncDecTarget(Node n) {
switch (n.getToken()) {
case NAME:
case GETPROP:
case GETELEM:
validateExpression(n);
break;
case CAST:
validateChildCount(n.getFirstChild(), 1);
validateIncDecTarget(n.getFirstChild());
break;
default:
violation("Invalid INC/DEC target " + n.getToken(), n);
}
}
private void validateUnaryOp(Node n) {
validateChildCount(n, 1);
validateExpression(n.getFirstChild());
}
private void validateBinaryOp(Node n) {
validateChildCount(n, 2);
validateExpression(n.getFirstChild());
validateExpression(n.getLastChild());
}
private void validateTrinaryOp(Node n) {
validateChildCount(n, 3);
Node first = n.getFirstChild();
validateExpression(first);
validateExpression(first.getNext());
validateExpression(n.getLastChild());
}
private void validateNamedType(Node n) {
validateNodeType(Token.NAMED_TYPE, n);
validateChildCount(n);
validateName(n.getFirstChild());
}
private void validateTypeAlias(Node n) {
validateFeature(Feature.TYPE_ALIAS, n);
validateNodeType(Token.TYPE_ALIAS, n);
validateChildCount(n);
}
private void validateAmbientDeclaration(Node n) {
validateFeature(Feature.AMBIENT_DECLARATION, n);
validateNodeType(Token.DECLARE, n);
validateAmbientDeclarationHelper(n.getFirstChild());
}
private void validateAmbientDeclarationHelper(Node n) {
switch (n.getToken()) {
case VAR:
case LET:
case CONST:
validateNameDeclarationHelper(n.getToken(), n);
break;
case FUNCTION:
validateFunctionSignature(n);
break;
case CLASS:
validateClassDeclaration(n, true);
break;
case ENUM:
validateEnum(n);
break;
case NAMESPACE:
validateNamespace(n, true);
break;
case TYPE_ALIAS:
validateTypeAlias(n);
break;
case EXPORT:
validateExport(n, true);
break;
default:
break;
}
}
private void validateNamespace(Node n, boolean isAmbient) {
validateFeature(Feature.NAMESPACE_DECLARATION, n);
validateNodeType(Token.NAMESPACE, n);
validateChildCount(n);
validateNamespaceName(n.getFirstChild());
validateNamespaceElements(n.getLastChild(), isAmbient);
}
private void validateNamespaceName(Node n) {
switch (n.getToken()) {
case NAME:
validateName(n);
break;
case GETPROP:
validateGetProp(n);
break;
default:
break;
}
}
private void validateNamespaceElements(Node n, boolean isAmbient) {
validateNodeType(Token.NAMESPACE_ELEMENTS, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
if (isAmbient) {
validateAmbientDeclarationHelper(c);
} else {
validateStatement(c);
}
}
}
private void violation(String message, Node n) {
violationHandler.handleViolation(message, n);
}
private void validateNodeType(Token type, Node n) {
if (n.getToken() != type) {
violation("Expected " + type + " but was " + n.getToken(), n);
}
}
private void validateChildCount(Node n) {
int expectedArity = Token.arity(n.getToken());
if (expectedArity != -1) {
validateChildCount(n, expectedArity);
}
}
private void validateChildCount(Node n, int expected) {
int count = n.getChildCount();
if (expected != count) {
violation("Expected " + expected + " children, but was " + count, n);
}
}
private void validateChildCountIn(Node n, int min, int max) {
int count = n.getChildCount();
if (count < min || count > max) {
violation("Expected child count in [" + min + ", " + max
+ "], but was " + count, n);
}
}
private void validateMinimumChildCount(Node n, int i) {
boolean valid = false;
if (i == 1) {
valid = n.hasChildren();
} else if (i == 2) {
valid = n.hasMoreThanOneChild();
} else {
valid = n.getChildCount() >= i;
}
if (!valid) {
violation("Expected at least " + i + " children, but was " + n.getChildCount(), n);
}
}
private void validateMaximumChildCount(Node n, int i) {
boolean valid = false;
if (i == 1) {
valid = !n.hasMoreThanOneChild();
} else if (i == -1) {
valid = true; // Varying number of children.
} else {
valid = n.getChildCount() <= i;
}
if (!valid) {
violation("Expected no more than " + i + " children, but was " + n.getChildCount(), n);
}
}
private void validateFeature(Feature feature, Node n) {
if (!n.isFromExterns() && !compiler.getFeatureSet().has(feature)) {
// Skip this check for externs because we don't need to complete transpilation on externs,
// and currently only transpile externs so that we can typecheck ES6+ features in externs.
violation("AST should not contain " + feature, n);
}
// Note: currentScript may be null if someone called validateStatement or validateExpression
if (!isScriptFeatureValidationEnabled || currentScript == null) {
return;
}
FeatureSet scriptFeatures = NodeUtil.getFeatureSetOfScript(currentScript);
if (scriptFeatures == null || !NodeUtil.getFeatureSetOfScript(currentScript).has(feature)) {
violation("SCRIPT node should be marked as containing feature " + feature, currentScript);
}
}
}