Function checkUnusedLocalsAndParameters

test/fixtures/snapshot/typescript.js:82111–82214

(nodeWithLocals, addDiagnostic)

                (ts.isVariableDeclaration(declaration) && ts.isForInOrOfStatement(declaration.parent.parent) || isImportedDeclaration(declaration)) && isIdentifierThatStartsWithUnderscore(declaration.name);
        }
        function checkUnusedLocalsAndParameters(nodeWithLocals, addDiagnostic) {
            // Ideally we could use the ImportClause directly as a key, but must wait until we have full ES6 maps. So must store key along with value.
            var unusedImports = new ts.Map();
            var unusedDestructures = new ts.Map();
            var unusedVariables = new ts.Map();
            nodeWithLocals.locals.forEach(function (local) {
                // If it's purely a type parameter, ignore, will be checked in `checkUnusedTypeParameters`.
                // If it's a type parameter merged with a parameter, check if the parameter-side is used.
                if (local.flags & 262144 /* SymbolFlags.TypeParameter */ ? !(local.flags & 3 /* SymbolFlags.Variable */ && !(local.isReferenced & 3 /* SymbolFlags.Variable */)) : local.isReferenced || local.exportSymbol) {
                    return;
                }
                if (local.declarations) {
                    for (var _i = 0, _a = local.declarations; _i < _a.length; _i++) {
                        var declaration = _a[_i];
                        if (isValidUnusedLocalDeclaration(declaration)) {
                            continue;
                        }
                        if (isImportedDeclaration(declaration)) {
                            addToGroup(unusedImports, importClauseFromImported(declaration), declaration, getNodeId);
                        }
                        else if (ts.isBindingElement(declaration) && ts.isObjectBindingPattern(declaration.parent)) {
                            // In `{ a, ...b }, `a` is considered used since it removes a property from `b`. `b` may still be unused though.
                            var lastElement = ts.last(declaration.parent.elements);
                            if (declaration === lastElement || !ts.last(declaration.parent.elements).dotDotDotToken) {
                                addToGroup(unusedDestructures, declaration.parent, declaration, getNodeId);
                            }
                        }
                        else if (ts.isVariableDeclaration(declaration)) {
                            addToGroup(unusedVariables, declaration.parent, declaration, getNodeId);
                        }
                        else {
                            var parameter = local.valueDeclaration && tryGetRootParameterDeclaration(local.valueDeclaration);
                            var name = local.valueDeclaration && ts.getNameOfDeclaration(local.valueDeclaration);
                            if (parameter && name) {
                                if (!ts.isParameterPropertyDeclaration(parameter, parameter.parent) && !ts.parameterIsThisKeyword(parameter) && !isIdentifierThatStartsWithUnderscore(name)) {
                                    if (ts.isBindingElement(declaration) && ts.isArrayBindingPattern(declaration.parent)) {
                                        addToGroup(unusedDestructures, declaration.parent, declaration, getNodeId);
                                    }
                                    else {
                                        addDiagnostic(parameter, 1 /* UnusedKind.Parameter */, ts.createDiagnosticForNode(name, ts.Diagnostics._0_is_declared_but_its_value_is_never_read, ts.symbolName(local)));
                                    }
                                }
                            }
                            else {
                                errorUnusedLocal(declaration, ts.symbolName(local), addDiagnostic);
                            }
                        }
                    }
                }
            });
            unusedImports.forEach(function (_a) {
                var importClause = _a[0], unuseds = _a[1];
                var importDecl = importClause.parent;
                var nDeclarations = (importClause.name ? 1 : 0) +
                    (importClause.namedBindings ?
                        (importClause.namedBindings.kind === 268 /* SyntaxKind.NamespaceImport */ ? 1 : importClause.namedBindings.elements.length)
                        : 0);
                if (nDeclarations === unuseds.length) {