@mysql/xdevapi/test/unit/DevAPI/Expr.js

MySQL Connector/Node.js - A Node.js driver for MySQL using the X Protocol and X DevAPI.

/*
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 *
 * This program is free software; you can redistribute it and/or modify
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 * published by the Free Software Foundation.
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'use strict';

/* eslint-env node, mocha */

const { DataModel } = require('../../../lib/Protocol/Stubs/mysqlx_crud_pb');
const expect = require('chai').expect;
const td = require('testdouble');

// subject under test needs to be reloaded with test doubles
let Expr = require('../../../lib/DevAPI/Expr');

describe('Expr informal type', () => {
    afterEach('restore original dependencies', () => {
        td.reset();
    });

    context('getExpressionString()', () => {
        it('returns the original string encapsulated by the X DevAPI expression instance', () => {
            const value = 'foo';
            let expr = Expr({ value });
            let isLiteral = td.replace(expr, 'isLiteral');

            td.when(isLiteral()).thenReturn(true);
            expect(expr.getExpressionString()).to.equal(value);

            expr = Expr({ value: expr });
            isLiteral = td.replace(expr, 'isLiteral');

            td.when(isLiteral()).thenReturn(false);
            expect(expr.getExpressionString()).to.equal(value);
        });
    });

    context('getValue()', () => {
        let ExprParser, parseTableModeExpr, parseDocumentModeExpr;

        beforeEach('replace dependencies with test doubles', () => {
            ExprParser = td.replace('../../../lib/ExprParser');
            parseDocumentModeExpr = td.function();
            parseTableModeExpr = td.function();

            td.when(ExprParser()).thenReturn({ parse: parseDocumentModeExpr });
            td.when(ExprParser({ mode: DataModel.TABLE })).thenReturn({ parse: parseTableModeExpr });

            // reload module with the replacements
            Expr = require('../../../lib/DevAPI/Expr');
        });

        it('returns a parsed version of a projection expression string in the DOCUMENT data model by default', () => {
            const value = 'foo';
            const expr = Expr();
            const getExpressionString = td.replace(expr, 'getExpressionString');
            const parsedValue = 'bar';

            td.when(getExpressionString()).thenReturn(value);
            td.when(parseDocumentModeExpr(value)).thenReturn(parsedValue);

            expect(expr.getValue()).to.equal(parsedValue);
        });
    });

    context('isLiteral()', () => {
        it('checks whether the underlying value of the expression instance is a literal or an expression instance itself', () => {
            // eslint-disable-next-line no-unused-expressions
            expect(Expr({ value: 'foo' }).isLiteral()).to.be.true;
            return expect(Expr({ value: Expr({ value: 'foo' }) }).isLiteral()).to.be.false;
        });
    });
});