ts-flex-query/operators/convenience/let-if-defined.js

Flexible and type-safe data queries

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.letIfDefined = letIfDefined;
exports.unwrapLetIfDefined = unwrapLetIfDefined;
const lodash_1 = require("lodash");
const expressions_1 = require("../../expressions");
const helpers_1 = require("../../helpers");
const object_value_selector_1 = require("../../helpers/object-value-selector");
const if_1 = require("../basic/if");
const func_1 = require("./func");
const let_1 = require("./let");
const no_op_1 = require("./no-op");
const value_1 = require("./value");
const nullCheckFunction = () => (0, func_1.func)('in', (0, no_op_1.noOp)(), (0, value_1.value)([null, undefined]));
/** Applies the given selector if the input is defined. Otherwise, the input value (null or undefined) is propagated. */
function letIfDefined(selector) {
    return (0, let_1.letIn)((0, if_1.ifThenElse)(nullCheckFunction(), (0, no_op_1.noOp)(), (0, object_value_selector_1.createQueryFromObjectValueSelector)(selector)));
}
/** Unwraps an expression which was created using the @see letIfDefined operator.  */
function unwrapLetIfDefinedInternal(expression) {
    let inputVariable;
    let baseExpression;
    let ifExpression;
    if (expression instanceof expressions_1.LetExpression) {
        inputVariable = new expressions_1.VariableExpression(expression.input.dataType, expression.variableSymbol);
        baseExpression = expression.input;
        if (!(expression.body instanceof expressions_1.IfExpression)) {
            return undefined;
        }
        ifExpression = expression.body;
    }
    else if (expression instanceof expressions_1.IfExpression) {
        ifExpression = expression;
        if (!(expression.thenExpression instanceof expressions_1.VariableExpression)) {
            return undefined;
        }
        inputVariable = expression.thenExpression;
        baseExpression = inputVariable;
    }
    else {
        return undefined;
    }
    const conditionFunction = ifExpression.condition;
    const expectedFunction = (0, helpers_1.pipeExpression)(inputVariable, nullCheckFunction());
    if (!(0, lodash_1.isEqual)(conditionFunction, expectedFunction) || !(0, lodash_1.isEqual)(ifExpression.thenExpression, inputVariable)) {
        return undefined;
    }
    return {
        baseExpression,
        baseExpressionVariableSymbol: inputVariable.symbol,
        body: ifExpression.elseExpression
    };
}
/** Unwraps an expression which was created using the @see letIfDefined operator.  */
function unwrapLetIfDefined(expression) {
    return unwrapLetIfDefinedInternal(expression);
}
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