296 lines
13 KiB
JavaScript
296 lines
13 KiB
JavaScript
|
"use strict";
|
||
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
|
exports.callExpressionAffectsControlFlow = exports.SignatureEffect = exports.getControlFlowEnd = exports.endsControlFlow = void 0;
|
||
|
|
const ts = require("typescript");
|
||
|
|
const node_1 = require("../typeguard/node");
|
||
|
|
const util_1 = require("./util");
|
||
|
|
function endsControlFlow(statement, checker) {
|
||
|
|
return getControlFlowEnd(statement, checker).end;
|
||
|
|
}
|
||
|
|
exports.endsControlFlow = endsControlFlow;
|
||
|
|
const defaultControlFlowEnd = { statements: [], end: false };
|
||
|
|
function getControlFlowEnd(statement, checker) {
|
||
|
|
return node_1.isBlockLike(statement) ? handleBlock(statement, checker) : getControlFlowEndWorker(statement, checker);
|
||
|
|
}
|
||
|
|
exports.getControlFlowEnd = getControlFlowEnd;
|
||
|
|
function getControlFlowEndWorker(statement, checker) {
|
||
|
|
switch (statement.kind) {
|
||
|
|
case ts.SyntaxKind.ReturnStatement:
|
||
|
|
case ts.SyntaxKind.ThrowStatement:
|
||
|
|
case ts.SyntaxKind.ContinueStatement:
|
||
|
|
case ts.SyntaxKind.BreakStatement:
|
||
|
|
return { statements: [statement], end: true };
|
||
|
|
case ts.SyntaxKind.Block:
|
||
|
|
return handleBlock(statement, checker);
|
||
|
|
case ts.SyntaxKind.ForStatement:
|
||
|
|
case ts.SyntaxKind.WhileStatement:
|
||
|
|
return handleForAndWhileStatement(statement, checker);
|
||
|
|
case ts.SyntaxKind.ForOfStatement:
|
||
|
|
case ts.SyntaxKind.ForInStatement:
|
||
|
|
return handleForInOrOfStatement(statement, checker);
|
||
|
|
case ts.SyntaxKind.DoStatement:
|
||
|
|
return matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
|
||
|
|
case ts.SyntaxKind.IfStatement:
|
||
|
|
return handleIfStatement(statement, checker);
|
||
|
|
case ts.SyntaxKind.SwitchStatement:
|
||
|
|
return matchBreakOrContinue(handleSwitchStatement(statement, checker), node_1.isBreakStatement);
|
||
|
|
case ts.SyntaxKind.TryStatement:
|
||
|
|
return handleTryStatement(statement, checker);
|
||
|
|
case ts.SyntaxKind.LabeledStatement:
|
||
|
|
return matchLabel(getControlFlowEndWorker(statement.statement, checker), statement.label);
|
||
|
|
case ts.SyntaxKind.WithStatement:
|
||
|
|
return getControlFlowEndWorker(statement.statement, checker);
|
||
|
|
case ts.SyntaxKind.ExpressionStatement:
|
||
|
|
if (checker === undefined)
|
||
|
|
return defaultControlFlowEnd;
|
||
|
|
return handleExpressionStatement(statement, checker);
|
||
|
|
default:
|
||
|
|
return defaultControlFlowEnd;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
function handleBlock(statement, checker) {
|
||
|
|
const result = { statements: [], end: false };
|
||
|
|
for (const s of statement.statements) {
|
||
|
|
const current = getControlFlowEndWorker(s, checker);
|
||
|
|
result.statements.push(...current.statements);
|
||
|
|
if (current.end) {
|
||
|
|
result.end = true;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
function handleForInOrOfStatement(statement, checker) {
|
||
|
|
const end = matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
|
||
|
|
end.end = false; // loop body is guaranteed to be executed
|
||
|
|
return end;
|
||
|
|
}
|
||
|
|
function handleForAndWhileStatement(statement, checker) {
|
||
|
|
const constantCondition = statement.kind === ts.SyntaxKind.WhileStatement
|
||
|
|
? getConstantCondition(statement.expression)
|
||
|
|
: statement.condition === undefined || getConstantCondition(statement.condition);
|
||
|
|
if (constantCondition === false)
|
||
|
|
return defaultControlFlowEnd; // loop body is never executed
|
||
|
|
const end = matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
|
||
|
|
if (constantCondition === undefined)
|
||
|
|
end.end = false; // can't be sure that loop body is executed at all
|
||
|
|
return end;
|
||
|
|
}
|
||
|
|
/** Simply detects `true` and `false` in conditions. That matches TypeScript's behavior. */
|
||
|
|
function getConstantCondition(node) {
|
||
|
|
switch (node.kind) {
|
||
|
|
case ts.SyntaxKind.TrueKeyword:
|
||
|
|
return true;
|
||
|
|
case ts.SyntaxKind.FalseKeyword:
|
||
|
|
return false;
|
||
|
|
default:
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
function handleIfStatement(node, checker) {
|
||
|
|
switch (getConstantCondition(node.expression)) {
|
||
|
|
case true:
|
||
|
|
// else branch is never executed
|
||
|
|
return getControlFlowEndWorker(node.thenStatement, checker);
|
||
|
|
case false:
|
||
|
|
// then branch is never executed
|
||
|
|
return node.elseStatement === undefined
|
||
|
|
? defaultControlFlowEnd
|
||
|
|
: getControlFlowEndWorker(node.elseStatement, checker);
|
||
|
|
}
|
||
|
|
const then = getControlFlowEndWorker(node.thenStatement, checker);
|
||
|
|
if (node.elseStatement === undefined)
|
||
|
|
return {
|
||
|
|
statements: then.statements,
|
||
|
|
end: false,
|
||
|
|
};
|
||
|
|
const elze = getControlFlowEndWorker(node.elseStatement, checker);
|
||
|
|
return {
|
||
|
|
statements: [...then.statements, ...elze.statements],
|
||
|
|
end: then.end && elze.end,
|
||
|
|
};
|
||
|
|
}
|
||
|
|
function handleSwitchStatement(node, checker) {
|
||
|
|
let hasDefault = false;
|
||
|
|
const result = {
|
||
|
|
statements: [],
|
||
|
|
end: false,
|
||
|
|
};
|
||
|
|
for (const clause of node.caseBlock.clauses) {
|
||
|
|
if (clause.kind === ts.SyntaxKind.DefaultClause)
|
||
|
|
hasDefault = true;
|
||
|
|
const current = handleBlock(clause, checker);
|
||
|
|
result.end = current.end;
|
||
|
|
result.statements.push(...current.statements);
|
||
|
|
}
|
||
|
|
result.end && (result.end = hasDefault || checker !== undefined && util_1.hasExhaustiveCaseClauses(node, checker));
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
function handleTryStatement(node, checker) {
|
||
|
|
let finallyResult;
|
||
|
|
if (node.finallyBlock !== undefined) {
|
||
|
|
finallyResult = handleBlock(node.finallyBlock, checker);
|
||
|
|
// if 'finally' always ends control flow, we are not interested in any jump statements from 'try' or 'catch'
|
||
|
|
if (finallyResult.end)
|
||
|
|
return finallyResult;
|
||
|
|
}
|
||
|
|
const tryResult = handleBlock(node.tryBlock, checker);
|
||
|
|
if (node.catchClause === undefined)
|
||
|
|
return { statements: finallyResult.statements.concat(tryResult.statements), end: tryResult.end };
|
||
|
|
const catchResult = handleBlock(node.catchClause.block, checker);
|
||
|
|
return {
|
||
|
|
statements: tryResult.statements
|
||
|
|
// remove all throw statements and throwing function calls from the list of control flow statements inside tryBlock
|
||
|
|
.filter((s) => s.kind !== ts.SyntaxKind.ThrowStatement && s.kind !== ts.SyntaxKind.ExpressionStatement)
|
||
|
|
.concat(catchResult.statements, finallyResult === undefined ? [] : finallyResult.statements),
|
||
|
|
end: tryResult.end && catchResult.end, // only ends control flow if try AND catch definitely end control flow
|
||
|
|
};
|
||
|
|
}
|
||
|
|
/** Dotted name as TypeScript requires it for assertion signatures to affect control flow. */
|
||
|
|
function isDottedNameWithExplicitTypeAnnotation(node, checker) {
|
||
|
|
while (true) {
|
||
|
|
switch (node.kind) {
|
||
|
|
case ts.SyntaxKind.Identifier: {
|
||
|
|
const symbol = checker.getExportSymbolOfSymbol(checker.getSymbolAtLocation(node));
|
||
|
|
return isExplicitlyTypedSymbol(util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Alias) ? checker.getAliasedSymbol(symbol) : symbol, checker);
|
||
|
|
}
|
||
|
|
case ts.SyntaxKind.ThisKeyword:
|
||
|
|
return isExplicitlyTypedThis(node);
|
||
|
|
case ts.SyntaxKind.SuperKeyword:
|
||
|
|
return true;
|
||
|
|
case ts.SyntaxKind.PropertyAccessExpression:
|
||
|
|
if (!isExplicitlyTypedSymbol(checker.getSymbolAtLocation(node), checker))
|
||
|
|
return false;
|
||
|
|
// falls through
|
||
|
|
case ts.SyntaxKind.ParenthesizedExpression:
|
||
|
|
node = node.expression;
|
||
|
|
continue;
|
||
|
|
default:
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
function isExplicitlyTypedSymbol(symbol, checker) {
|
||
|
|
if (symbol === undefined)
|
||
|
|
return false;
|
||
|
|
if (util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Function | ts.SymbolFlags.Method | ts.SymbolFlags.Class | ts.SymbolFlags.ValueModule))
|
||
|
|
return true;
|
||
|
|
if (!util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Variable | ts.SymbolFlags.Property))
|
||
|
|
return false;
|
||
|
|
if (symbol.valueDeclaration === undefined)
|
||
|
|
return false;
|
||
|
|
if (declarationHasExplicitTypeAnnotation(symbol.valueDeclaration))
|
||
|
|
return true;
|
||
|
|
return node_1.isVariableDeclaration(symbol.valueDeclaration) &&
|
||
|
|
symbol.valueDeclaration.parent.parent.kind === ts.SyntaxKind.ForOfStatement &&
|
||
|
|
isDottedNameWithExplicitTypeAnnotation(symbol.valueDeclaration.parent.parent.expression, checker);
|
||
|
|
}
|
||
|
|
function declarationHasExplicitTypeAnnotation(node) {
|
||
|
|
if (ts.isJSDocPropertyLikeTag(node))
|
||
|
|
return node.typeExpression !== undefined;
|
||
|
|
return (node_1.isVariableDeclaration(node) ||
|
||
|
|
node_1.isParameterDeclaration(node) ||
|
||
|
|
node_1.isPropertyDeclaration(node) ||
|
||
|
|
node_1.isPropertySignature(node)) && (util_1.isNodeFlagSet(node, ts.NodeFlags.JavaScriptFile)
|
||
|
|
? ts.getJSDocType(node)
|
||
|
|
: node.type) !== undefined;
|
||
|
|
}
|
||
|
|
function isExplicitlyTypedThis(node) {
|
||
|
|
var _a;
|
||
|
|
do {
|
||
|
|
node = node.parent;
|
||
|
|
if (node_1.isDecorator(node)) {
|
||
|
|
// `this` in decorators always resolves outside of the containing class
|
||
|
|
if (node.parent.kind === ts.SyntaxKind.Parameter && node_1.isClassLikeDeclaration(node.parent.parent.parent)) {
|
||
|
|
node = node.parent.parent.parent.parent;
|
||
|
|
}
|
||
|
|
else if (node_1.isClassLikeDeclaration(node.parent.parent)) {
|
||
|
|
node = node.parent.parent.parent;
|
||
|
|
}
|
||
|
|
else if (node_1.isClassLikeDeclaration(node.parent)) {
|
||
|
|
node = node.parent.parent;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} while (util_1.isFunctionScopeBoundary(node) !== 1 /* Function */ || node.kind === ts.SyntaxKind.ArrowFunction);
|
||
|
|
return util_1.isFunctionWithBody(node) &&
|
||
|
|
(util_1.isNodeFlagSet(node, ts.NodeFlags.JavaScriptFile)
|
||
|
|
? ((_a = ts.getJSDocThisTag(node)) === null || _a === void 0 ? void 0 : _a.typeExpression) !== undefined
|
||
|
|
: node.parameters.length !== 0 && util_1.isThisParameter(node.parameters[0]) && node.parameters[0].type !== undefined) ||
|
||
|
|
node_1.isClassLikeDeclaration(node.parent);
|
||
|
|
}
|
||
|
|
var SignatureEffect;
|
||
|
|
(function (SignatureEffect) {
|
||
|
|
SignatureEffect[SignatureEffect["Never"] = 1] = "Never";
|
||
|
|
SignatureEffect[SignatureEffect["Asserts"] = 2] = "Asserts";
|
||
|
|
})(SignatureEffect = exports.SignatureEffect || (exports.SignatureEffect = {}));
|
||
|
|
/**
|
||
|
|
* Dermines whether a top level CallExpression has a control flow effect according to TypeScript's rules.
|
||
|
|
* This handles functions returning `never` and `asserts`.
|
||
|
|
*/
|
||
|
|
function callExpressionAffectsControlFlow(node, checker) {
|
||
|
|
var _a, _b, _c;
|
||
|
|
if (!node_1.isExpressionStatement(node.parent) ||
|
||
|
|
ts.isOptionalChain(node) ||
|
||
|
|
!isDottedNameWithExplicitTypeAnnotation(node.expression, checker))
|
||
|
|
return;
|
||
|
|
const signature = checker.getResolvedSignature(node);
|
||
|
|
if ((signature === null || signature === void 0 ? void 0 : signature.declaration) === undefined)
|
||
|
|
return;
|
||
|
|
const typeNode = ts.isJSDocSignature(signature.declaration)
|
||
|
|
? (_b = (_a = signature.declaration.type) === null || _a === void 0 ? void 0 : _a.typeExpression) === null || _b === void 0 ? void 0 : _b.type
|
||
|
|
: (_c = signature.declaration.type) !== null && _c !== void 0 ? _c : (util_1.isNodeFlagSet(signature.declaration, ts.NodeFlags.JavaScriptFile)
|
||
|
|
? ts.getJSDocReturnType(signature.declaration)
|
||
|
|
: undefined);
|
||
|
|
if (typeNode === undefined)
|
||
|
|
return;
|
||
|
|
if (node_1.isTypePredicateNode(typeNode) && typeNode.assertsModifier !== undefined)
|
||
|
|
return 2 /* Asserts */;
|
||
|
|
return util_1.isTypeFlagSet(checker.getTypeFromTypeNode(typeNode), ts.TypeFlags.Never) ? 1 /* Never */ : undefined;
|
||
|
|
}
|
||
|
|
exports.callExpressionAffectsControlFlow = callExpressionAffectsControlFlow;
|
||
|
|
function handleExpressionStatement(node, checker) {
|
||
|
|
if (!node_1.isCallExpression(node.expression))
|
||
|
|
return defaultControlFlowEnd;
|
||
|
|
switch (callExpressionAffectsControlFlow(node.expression, checker)) {
|
||
|
|
case 2 /* Asserts */:
|
||
|
|
return { statements: [node], end: false };
|
||
|
|
case 1 /* Never */:
|
||
|
|
return { statements: [node], end: true };
|
||
|
|
case undefined:
|
||
|
|
return defaultControlFlowEnd;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
function matchBreakOrContinue(current, pred) {
|
||
|
|
const result = {
|
||
|
|
statements: [],
|
||
|
|
end: current.end,
|
||
|
|
};
|
||
|
|
for (const statement of current.statements) {
|
||
|
|
if (pred(statement) && statement.label === undefined) {
|
||
|
|
result.end = false;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
result.statements.push(statement);
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
function matchLabel(current, label) {
|
||
|
|
const result = {
|
||
|
|
statements: [],
|
||
|
|
end: current.end,
|
||
|
|
};
|
||
|
|
const labelText = label.text;
|
||
|
|
for (const statement of current.statements) {
|
||
|
|
switch (statement.kind) {
|
||
|
|
case ts.SyntaxKind.BreakStatement:
|
||
|
|
case ts.SyntaxKind.ContinueStatement:
|
||
|
|
if (statement.label !== undefined && statement.label.text === labelText) {
|
||
|
|
result.end = false;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
result.statements.push(statement);
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
//# sourceMappingURL=control-flow.js.map
|