Groovy example source code file (JsonLexerTest.groovy)

This example Groovy source code file (JsonLexerTest.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

close_curly, colon, comma, comma, json, jsonlexer, jsonlexer, number, open_curly, string, string, stringreader, stringreader, true

The Groovy JsonLexerTest.groovy source code

/*
 * Copyright 2003-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package groovy.json

import static groovy.json.JsonTokenType.*
import groovy.io.LineColumnReader

/**
 * @author Guillaume Laforge
 */
class JsonLexerTest extends GroovyTestCase {

    void testSkipWhitespace() {
        def content = "    true"
        def reader = new LineColumnReader(new StringReader(content))

        def lexer = new JsonLexer(reader)
        lexer.skipWhitespace()

        def charsLeftRead = new char[4]
        reader.read(charsLeftRead)

        assert new String(charsLeftRead) == "true"
    }

    void testNextToken() {
        def content = [" true ", " false ", " null ", " -123.456e78 ", " [ ", " ] ", " { ", " } ", " : ", " , "]

        assert content.collect {
            def lexer = new JsonLexer(new StringReader(it))
            lexer.nextToken().type
        } == [
                TRUE, FALSE, NULL, NUMBER,
                OPEN_BRACKET, CLOSE_BRACKET, OPEN_CURLY, CLOSE_CURLY, COLON, COMMA
        ]
    }

    void testSuiteOfTokens() {
        def content = ' [ true, null, false, { "a" : 1, "b": "hi"}, 12.34 ] '
        def lexer = new JsonLexer(new StringReader(content))

        def output = lexer.collect { it.toString() }

        assert output == [
                "[ (OPEN_BRACKET) [1:2-1:3]",
                "true (TRUE) [1:4-1:8]",
                ", (COMMA) [1:8-1:9]",
                "null (NULL) [1:10-1:14]",
                ", (COMMA) [1:14-1:15]",
                "false (FALSE) [1:16-1:21]",
                ", (COMMA) [1:21-1:22]",
                "{ (OPEN_CURLY) [1:23-1:24]",
                '"a" (STRING) [1:25-1:28]',
                ": (COLON) [1:29-1:30]",
                "1 (NUMBER) [1:31-1:32]",
                ", (COMMA) [1:32-1:33]",
                '"b" (STRING) [1:34-1:37]',
                ": (COLON) [1:37-1:38]",
                '"hi" (STRING) [1:39-1:43]',
                "} (CLOSE_CURLY) [1:43-1:44]",
                ", (COMMA) [1:44-1:45]",
                "12.34 (NUMBER) [1:46-1:51]",
                "] (CLOSE_BRACKET) [1:52-1:53]"
        ]
    }

    void testBeginningOfAValidToken() {
        def content = "  truaaa "
        def lexer = new JsonLexer(new StringReader(content))

        def msg = shouldFail(JsonException) {
            lexer.nextToken()
        }

        assert msg.contains("trua")
        assert msg.contains("constant 'true'")
        assert msg.contains("column: 7")
    }

    void testBeginningOfValidNumber() {
        def content = " 2134.432a"
        def lexer = new JsonLexer(new StringReader(content))

        assert lexer.nextToken().text == "2134.432"
        shouldFail(JsonException) {
            lexer.nextToken()
        }
    }

    void testIteratorRemoveUnimplemented() {
        def lexer = new JsonLexer(new StringReader(""))

        shouldFail(UnsupportedOperationException) {
            lexer.remove()
        }
    }

    void testUnescapingWithLexer() {
        def lexer = new JsonLexer(new StringReader('"\\' + 'u004A\\' + 'u0053\\' + 'u004F\\' + 'u004E"'))

        assert lexer.nextToken().value == 'JSON'
    }

    void testUnescaping() {
        assert JsonLexer.unescape('\\b') == '\b'
        assert JsonLexer.unescape('\\f') == '\f'
        assert JsonLexer.unescape('\\n') == '\n'
        assert JsonLexer.unescape('\\r') == '\r'
        assert JsonLexer.unescape('\\t') == '\t'
        assert JsonLexer.unescape('\\\\') == '\\'
        assert JsonLexer.unescape('\\/') == '/'
        assert JsonLexer.unescape('\\"') == '"'

        assert JsonLexer.unescape('\\' + 'u004A\\' + 'u0053\\' + 'u004F\\' + 'u004E') == 'JSON'
    }

    void testBackSlashEscaping() {
        def lexer = new JsonLexer(new StringReader('["Guill\\\\aume"]'))

        assert lexer.nextToken().type == JsonTokenType.OPEN_BRACKET
        assert lexer.nextToken().value == "Guill\\aume"
        assert lexer.nextToken().type == JsonTokenType.CLOSE_BRACKET
        assert lexer.nextToken() == null
    }
}