Function collectReadsAndWrites

test/fixtures/snapshot/typescript.js:161297–161633

(targetRange, scopes, enclosingTextRange, sourceFile, checker, cancellationToken)

                Usage[Usage["Write"] = 2] = "Write";
            })(Usage || (Usage = {}));
            function collectReadsAndWrites(targetRange, scopes, enclosingTextRange, sourceFile, checker, cancellationToken) {
                var allTypeParameterUsages = new ts.Map(); // Key is type ID
                var usagesPerScope = [];
                var substitutionsPerScope = [];
                var functionErrorsPerScope = [];
                var constantErrorsPerScope = [];
                var visibleDeclarationsInExtractedRange = [];
                var exposedVariableSymbolSet = new ts.Map(); // Key is symbol ID
                var exposedVariableDeclarations = [];
                var firstExposedNonVariableDeclaration;
                var expression = !isReadonlyArray(targetRange.range)
                    ? targetRange.range
                    : targetRange.range.length === 1 && ts.isExpressionStatement(targetRange.range[0])
                        ? targetRange.range[0].expression
                        : undefined;
                var expressionDiagnostic;
                if (expression === undefined) {
                    var statements = targetRange.range;
                    var start = ts.first(statements).getStart();
                    var end = ts.last(statements).end;
                    expressionDiagnostic = ts.createFileDiagnostic(sourceFile, start, end - start, Messages.expressionExpected);
                }
                else if (checker.getTypeAtLocation(expression).flags & (16384 /* TypeFlags.Void */ | 131072 /* TypeFlags.Never */)) {
                    expressionDiagnostic = ts.createDiagnosticForNode(expression, Messages.uselessConstantType);
                }
                // initialize results
                for (var _i = 0, scopes_1 = scopes; _i < scopes_1.length; _i++) {
                    var scope = scopes_1[_i];
                    usagesPerScope.push({ usages: new ts.Map(), typeParameterUsages: new ts.Map(), substitutions: new ts.Map() });
                    substitutionsPerScope.push(new ts.Map());
                    functionErrorsPerScope.push([]);
                    var constantErrors = [];
                    if (expressionDiagnostic) {
                        constantErrors.push(expressionDiagnostic);
                    }
                    if (ts.isClassLike(scope) && ts.isInJSFile(scope)) {
                        constantErrors.push(ts.createDiagnosticForNode(scope, Messages.cannotExtractToJSClass));
                    }
                    if (ts.isArrowFunction(scope) && !ts.isBlock(scope.body)) {
                        // TODO (https://github.com/Microsoft/TypeScript/issues/18924): allow this
                        constantErrors.push(ts.createDiagnosticForNode(scope, Messages.cannotExtractToExpressionArrowFunction));
                    }
                    constantErrorsPerScope.push(constantErrors);
                }
                var seenUsages = new ts.Map();
                var target = isReadonlyArray(targetRange.range) ? ts.factory.createBlock(targetRange.range) : targetRange.range;
                var unmodifiedNode = isReadonlyArray(targetRange.range) ? ts.first(targetRange.range) : targetRange.range;
                var inGenericContext = isInGenericContext(unmodifiedNode);
                collectUsages(target);
                // Unfortunately, this code takes advantage of the knowledge that the generated method
                // will use the contextual type of an expression as the return type of the extracted
                // method (and will therefore "use" all the types involved).
                if (inGenericContext && !isReadonlyArray(targetRange.range) && !ts.isJsxAttribute(targetRange.range)) {
                    var contextualType = checker.getContextualType(targetRange.range); // TODO: GH#18217
                    recordTypeParameterUsages(contextualType);
                }
                if (allTypeParameterUsages.size > 0) {
                    var seenTypeParameterUsages = new ts.Map(); // Key is type ID