| 1 | "use strict";
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| 2 | Object.defineProperty(exports, "__esModule", { value: true });
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| 3 | exports.callExpressionAffectsControlFlow = exports.SignatureEffect = exports.getControlFlowEnd = exports.endsControlFlow = void 0;
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| 4 | const ts = require("typescript");
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| 5 | const node_1 = require("../typeguard/node");
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| 6 | const util_1 = require("./util");
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| 7 | function endsControlFlow(statement, checker) {
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| 8 | return getControlFlowEnd(statement, checker).end;
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| 9 | }
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| 10 | exports.endsControlFlow = endsControlFlow;
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| 11 | const defaultControlFlowEnd = { statements: [], end: false };
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| 12 | function getControlFlowEnd(statement, checker) {
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| 13 | return node_1.isBlockLike(statement) ? handleBlock(statement, checker) : getControlFlowEndWorker(statement, checker);
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| 14 | }
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| 15 | exports.getControlFlowEnd = getControlFlowEnd;
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| 16 | function getControlFlowEndWorker(statement, checker) {
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| 17 | switch (statement.kind) {
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| 18 | case ts.SyntaxKind.ReturnStatement:
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| 19 | case ts.SyntaxKind.ThrowStatement:
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| 20 | case ts.SyntaxKind.ContinueStatement:
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| 21 | case ts.SyntaxKind.BreakStatement:
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| 22 | return { statements: [statement], end: true };
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| 23 | case ts.SyntaxKind.Block:
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| 24 | return handleBlock(statement, checker);
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| 25 | case ts.SyntaxKind.ForStatement:
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| 26 | case ts.SyntaxKind.WhileStatement:
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| 27 | return handleForAndWhileStatement(statement, checker);
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| 28 | case ts.SyntaxKind.ForOfStatement:
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| 29 | case ts.SyntaxKind.ForInStatement:
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| 30 | return handleForInOrOfStatement(statement, checker);
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| 31 | case ts.SyntaxKind.DoStatement:
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| 32 | return matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
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| 33 | case ts.SyntaxKind.IfStatement:
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| 34 | return handleIfStatement(statement, checker);
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| 35 | case ts.SyntaxKind.SwitchStatement:
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| 36 | return matchBreakOrContinue(handleSwitchStatement(statement, checker), node_1.isBreakStatement);
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| 37 | case ts.SyntaxKind.TryStatement:
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| 38 | return handleTryStatement(statement, checker);
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| 39 | case ts.SyntaxKind.LabeledStatement:
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| 40 | return matchLabel(getControlFlowEndWorker(statement.statement, checker), statement.label);
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| 41 | case ts.SyntaxKind.WithStatement:
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| 42 | return getControlFlowEndWorker(statement.statement, checker);
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| 43 | case ts.SyntaxKind.ExpressionStatement:
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| 44 | if (checker === undefined)
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| 45 | return defaultControlFlowEnd;
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| 46 | return handleExpressionStatement(statement, checker);
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| 47 | default:
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| 48 | return defaultControlFlowEnd;
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| 49 | }
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| 50 | }
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| 51 | function handleBlock(statement, checker) {
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| 52 | const result = { statements: [], end: false };
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| 53 | for (const s of statement.statements) {
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| 54 | const current = getControlFlowEndWorker(s, checker);
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| 55 | result.statements.push(...current.statements);
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| 56 | if (current.end) {
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| 57 | result.end = true;
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| 58 | break;
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| 59 | }
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| 60 | }
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| 61 | return result;
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| 62 | }
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| 63 | function handleForInOrOfStatement(statement, checker) {
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| 64 | const end = matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
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| 65 | end.end = false; // loop body is guaranteed to be executed
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| 66 | return end;
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| 67 | }
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| 68 | function handleForAndWhileStatement(statement, checker) {
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| 69 | const constantCondition = statement.kind === ts.SyntaxKind.WhileStatement
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| 70 | ? getConstantCondition(statement.expression)
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| 71 | : statement.condition === undefined || getConstantCondition(statement.condition);
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| 72 | if (constantCondition === false)
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| 73 | return defaultControlFlowEnd; // loop body is never executed
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| 74 | const end = matchBreakOrContinue(getControlFlowEndWorker(statement.statement, checker), node_1.isBreakOrContinueStatement);
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| 75 | if (constantCondition === undefined)
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| 76 | end.end = false; // can't be sure that loop body is executed at all
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| 77 | return end;
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| 78 | }
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| 79 | /** Simply detects `true` and `false` in conditions. That matches TypeScript's behavior. */
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| 80 | function getConstantCondition(node) {
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| 81 | switch (node.kind) {
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| 82 | case ts.SyntaxKind.TrueKeyword:
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| 83 | return true;
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| 84 | case ts.SyntaxKind.FalseKeyword:
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| 85 | return false;
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| 86 | default:
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| 87 | return;
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| 88 | }
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| 89 | }
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| 90 | function handleIfStatement(node, checker) {
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| 91 | switch (getConstantCondition(node.expression)) {
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| 92 | case true:
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| 93 | // else branch is never executed
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| 94 | return getControlFlowEndWorker(node.thenStatement, checker);
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| 95 | case false:
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| 96 | // then branch is never executed
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| 97 | return node.elseStatement === undefined
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| 98 | ? defaultControlFlowEnd
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| 99 | : getControlFlowEndWorker(node.elseStatement, checker);
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| 100 | }
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| 101 | const then = getControlFlowEndWorker(node.thenStatement, checker);
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| 102 | if (node.elseStatement === undefined)
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| 103 | return {
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| 104 | statements: then.statements,
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| 105 | end: false,
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| 106 | };
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| 107 | const elze = getControlFlowEndWorker(node.elseStatement, checker);
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| 108 | return {
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| 109 | statements: [...then.statements, ...elze.statements],
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| 110 | end: then.end && elze.end,
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| 111 | };
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| 112 | }
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| 113 | function handleSwitchStatement(node, checker) {
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| 114 | let hasDefault = false;
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| 115 | const result = {
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| 116 | statements: [],
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| 117 | end: false,
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| 118 | };
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| 119 | for (const clause of node.caseBlock.clauses) {
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| 120 | if (clause.kind === ts.SyntaxKind.DefaultClause)
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| 121 | hasDefault = true;
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| 122 | const current = handleBlock(clause, checker);
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| 123 | result.end = current.end;
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| 124 | result.statements.push(...current.statements);
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| 125 | }
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| 126 | result.end && (result.end = hasDefault || checker !== undefined && util_1.hasExhaustiveCaseClauses(node, checker));
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| 127 | return result;
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| 128 | }
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| 129 | function handleTryStatement(node, checker) {
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| 130 | let finallyResult;
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| 131 | if (node.finallyBlock !== undefined) {
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| 132 | finallyResult = handleBlock(node.finallyBlock, checker);
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| 133 | // if 'finally' always ends control flow, we are not interested in any jump statements from 'try' or 'catch'
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| 134 | if (finallyResult.end)
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| 135 | return finallyResult;
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| 136 | }
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| 137 | const tryResult = handleBlock(node.tryBlock, checker);
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| 138 | if (node.catchClause === undefined)
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| 139 | return { statements: finallyResult.statements.concat(tryResult.statements), end: tryResult.end };
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| 140 | const catchResult = handleBlock(node.catchClause.block, checker);
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| 141 | return {
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| 142 | statements: tryResult.statements
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| 143 | // remove all throw statements and throwing function calls from the list of control flow statements inside tryBlock
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| 144 | .filter((s) => s.kind !== ts.SyntaxKind.ThrowStatement && s.kind !== ts.SyntaxKind.ExpressionStatement)
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| 145 | .concat(catchResult.statements, finallyResult === undefined ? [] : finallyResult.statements),
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| 146 | end: tryResult.end && catchResult.end, // only ends control flow if try AND catch definitely end control flow
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| 147 | };
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| 148 | }
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| 149 | /** Dotted name as TypeScript requires it for assertion signatures to affect control flow. */
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| 150 | function isDottedNameWithExplicitTypeAnnotation(node, checker) {
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| 151 | while (true) {
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| 152 | switch (node.kind) {
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| 153 | case ts.SyntaxKind.Identifier: {
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| 154 | const symbol = checker.getExportSymbolOfSymbol(checker.getSymbolAtLocation(node));
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| 155 | return isExplicitlyTypedSymbol(util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Alias) ? checker.getAliasedSymbol(symbol) : symbol, checker);
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| 156 | }
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| 157 | case ts.SyntaxKind.ThisKeyword:
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| 158 | return isExplicitlyTypedThis(node);
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| 159 | case ts.SyntaxKind.SuperKeyword:
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| 160 | return true;
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| 161 | case ts.SyntaxKind.PropertyAccessExpression:
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| 162 | if (!isExplicitlyTypedSymbol(checker.getSymbolAtLocation(node), checker))
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| 163 | return false;
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| 164 | // falls through
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| 165 | case ts.SyntaxKind.ParenthesizedExpression:
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| 166 | node = node.expression;
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| 167 | continue;
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| 168 | default:
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| 169 | return false;
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| 170 | }
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| 171 | }
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| 172 | }
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| 173 | function isExplicitlyTypedSymbol(symbol, checker) {
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| 174 | if (symbol === undefined)
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| 175 | return false;
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| 176 | if (util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Function | ts.SymbolFlags.Method | ts.SymbolFlags.Class | ts.SymbolFlags.ValueModule))
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| 177 | return true;
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| 178 | if (!util_1.isSymbolFlagSet(symbol, ts.SymbolFlags.Variable | ts.SymbolFlags.Property))
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| 179 | return false;
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| 180 | if (symbol.valueDeclaration === undefined)
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| 181 | return false;
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| 182 | if (declarationHasExplicitTypeAnnotation(symbol.valueDeclaration))
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| 183 | return true;
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| 184 | return node_1.isVariableDeclaration(symbol.valueDeclaration) &&
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| 185 | symbol.valueDeclaration.parent.parent.kind === ts.SyntaxKind.ForOfStatement &&
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| 186 | isDottedNameWithExplicitTypeAnnotation(symbol.valueDeclaration.parent.parent.expression, checker);
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| 187 | }
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| 188 | function declarationHasExplicitTypeAnnotation(node) {
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| 189 | if (ts.isJSDocPropertyLikeTag(node))
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| 190 | return node.typeExpression !== undefined;
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| 191 | return (node_1.isVariableDeclaration(node) ||
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| 192 | node_1.isParameterDeclaration(node) ||
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| 193 | node_1.isPropertyDeclaration(node) ||
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| 194 | node_1.isPropertySignature(node)) && (util_1.isNodeFlagSet(node, ts.NodeFlags.JavaScriptFile)
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| 195 | ? ts.getJSDocType(node)
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| 196 | : node.type) !== undefined;
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| 197 | }
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| 198 | function isExplicitlyTypedThis(node) {
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| 199 | var _a;
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| 200 | do {
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| 201 | node = node.parent;
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| 202 | if (node_1.isDecorator(node)) {
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| 203 | // `this` in decorators always resolves outside of the containing class
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| 204 | if (node.parent.kind === ts.SyntaxKind.Parameter && node_1.isClassLikeDeclaration(node.parent.parent.parent)) {
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| 205 | node = node.parent.parent.parent.parent;
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| 206 | }
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| 207 | else if (node_1.isClassLikeDeclaration(node.parent.parent)) {
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| 208 | node = node.parent.parent.parent;
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| 209 | }
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| 210 | else if (node_1.isClassLikeDeclaration(node.parent)) {
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| 211 | node = node.parent.parent;
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| 212 | }
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| 213 | }
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| 214 | } while (util_1.isFunctionScopeBoundary(node) !== 1 /* Function */ || node.kind === ts.SyntaxKind.ArrowFunction);
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| 215 | return util_1.isFunctionWithBody(node) &&
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| 216 | (util_1.isNodeFlagSet(node, ts.NodeFlags.JavaScriptFile)
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| 217 | ? ((_a = ts.getJSDocThisTag(node)) === null || _a === void 0 ? void 0 : _a.typeExpression) !== undefined
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| 218 | : node.parameters.length !== 0 && util_1.isThisParameter(node.parameters[0]) && node.parameters[0].type !== undefined) ||
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| 219 | node_1.isClassLikeDeclaration(node.parent);
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| 220 | }
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| 221 | var SignatureEffect;
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| 222 | (function (SignatureEffect) {
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| 223 | SignatureEffect[SignatureEffect["Never"] = 1] = "Never";
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| 224 | SignatureEffect[SignatureEffect["Asserts"] = 2] = "Asserts";
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| 225 | })(SignatureEffect = exports.SignatureEffect || (exports.SignatureEffect = {}));
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| 226 | /**
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| 227 | * Dermines whether a top level CallExpression has a control flow effect according to TypeScript's rules.
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| 228 | * This handles functions returning `never` and `asserts`.
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| 229 | */
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| 230 | function callExpressionAffectsControlFlow(node, checker) {
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| 231 | var _a, _b, _c;
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| 232 | if (!node_1.isExpressionStatement(node.parent) ||
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| 233 | ts.isOptionalChain(node) ||
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| 234 | !isDottedNameWithExplicitTypeAnnotation(node.expression, checker))
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| 235 | return;
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| 236 | const signature = checker.getResolvedSignature(node);
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| 237 | if ((signature === null || signature === void 0 ? void 0 : signature.declaration) === undefined)
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| 238 | return;
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| 239 | const typeNode = ts.isJSDocSignature(signature.declaration)
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| 240 | ? (_b = (_a = signature.declaration.type) === null || _a === void 0 ? void 0 : _a.typeExpression) === null || _b === void 0 ? void 0 : _b.type
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| 241 | : (_c = signature.declaration.type) !== null && _c !== void 0 ? _c : (util_1.isNodeFlagSet(signature.declaration, ts.NodeFlags.JavaScriptFile)
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| 242 | ? ts.getJSDocReturnType(signature.declaration)
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| 243 | : undefined);
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| 244 | if (typeNode === undefined)
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| 245 | return;
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| 246 | if (node_1.isTypePredicateNode(typeNode) && typeNode.assertsModifier !== undefined)
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| 247 | return 2 /* Asserts */;
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| 248 | return util_1.isTypeFlagSet(checker.getTypeFromTypeNode(typeNode), ts.TypeFlags.Never) ? 1 /* Never */ : undefined;
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| 249 | }
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| 250 | exports.callExpressionAffectsControlFlow = callExpressionAffectsControlFlow;
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| 251 | function handleExpressionStatement(node, checker) {
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| 252 | if (!node_1.isCallExpression(node.expression))
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| 253 | return defaultControlFlowEnd;
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| 254 | switch (callExpressionAffectsControlFlow(node.expression, checker)) {
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| 255 | case 2 /* Asserts */:
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| 256 | return { statements: [node], end: false };
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| 257 | case 1 /* Never */:
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| 258 | return { statements: [node], end: true };
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| 259 | case undefined:
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| 260 | return defaultControlFlowEnd;
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| 261 | }
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| 262 | }
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| 263 | function matchBreakOrContinue(current, pred) {
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| 264 | const result = {
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| 265 | statements: [],
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| 266 | end: current.end,
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| 267 | };
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| 268 | for (const statement of current.statements) {
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| 269 | if (pred(statement) && statement.label === undefined) {
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| 270 | result.end = false;
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| 271 | continue;
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| 272 | }
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| 273 | result.statements.push(statement);
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| 274 | }
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| 275 | return result;
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| 276 | }
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| 277 | function matchLabel(current, label) {
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| 278 | const result = {
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| 279 | statements: [],
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| 280 | end: current.end,
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| 281 | };
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| 282 | const labelText = label.text;
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| 283 | for (const statement of current.statements) {
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| 284 | switch (statement.kind) {
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| 285 | case ts.SyntaxKind.BreakStatement:
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| 286 | case ts.SyntaxKind.ContinueStatement:
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| 287 | if (statement.label !== undefined && statement.label.text === labelText) {
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| 288 | result.end = false;
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| 289 | continue;
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| 290 | }
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| 291 | }
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| 292 | result.statements.push(statement);
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| 293 | }
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| 294 | return result;
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| 295 | }
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| 296 | //# sourceMappingURL=control-flow.js.map |
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