JsonWriterTest.java

/*******************************************************************************
 * Copyright (c) 2012-2016 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.everrest.core.impl.provider.json;

import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import java.io.StringWriter;
import java.io.Writer;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

public class JsonWriterTest {
    @Rule
    public ExpectedException thrown = ExpectedException.none();

    private JsonWriter   jsonWriter;
    private StringWriter writer;

    @Before
    public void setUp() throws Exception {
        writer = new StringWriter();
        jsonWriter = new JsonWriter(writer);
    }

    @Test
    public void writesEmptyObject() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        assertEquals("{}", writer.toString());
    }

    @Test
    public void writesKeyBeforeObject() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        jsonWriter.writeEndObject();
        assertEquals("{\"key\":{}}", writer.toString());
    }

    @Test
    public void writesObjectsSeparatedByComma() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key1");
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        jsonWriter.writeKey("key2");
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        jsonWriter.writeEndObject();
        assertEquals("{\"key1\":{},\"key2\":{}}", writer.toString());
    }

    @Test
    public void writesEmptyArray() throws Exception {
        jsonWriter.writeStartArray();
        jsonWriter.writeEndArray();
        assertEquals("[]", writer.toString());
    }

    @Test
    public void writesObjectsAsItemsOfArray() throws Exception {
        jsonWriter.writeStartArray();
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        jsonWriter.writeStartObject();
        jsonWriter.writeEndObject();
        jsonWriter.writeEndArray();
        assertEquals("[{},{}]", writer.toString());
    }

    @Test
    public void failsWriteStartObjectWhenItDoesNotStartRootObjectOrDoesNotFollowKey() throws Exception {
        jsonWriter.writeStartObject();

        thrown.expect(JsonException.class);
        jsonWriter.writeStartObject();
    }

    @Test
    public void failsWhenEndObjectIsBeforeStartObject() throws Exception {
        thrown.expect(JsonException.class);
        jsonWriter.writeEndObject();
    }

    @Test
    public void writesStartArrayAfterKey() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeStartArray();
        jsonWriter.writeEndArray();
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":[]}", writer.toString());
    }

    @Test
    public void writesMultiDimensionArray() throws Exception {
        jsonWriter.writeStartArray();
        jsonWriter.writeStartArray();
        jsonWriter.writeEndArray();
        jsonWriter.writeStartArray();
        jsonWriter.writeEndArray();
        jsonWriter.writeEndArray();

        assertEquals("[[],[]]", writer.toString());
    }

    @Test
    public void failsWriteStartArrayWhenItDoesNotStartRootArrayOrDoesNotFollowKey() throws Exception {
        jsonWriter.writeStartObject();

        thrown.expect(JsonException.class);
        jsonWriter.writeStartArray();
    }

    @Test
    public void failsWhenEndArrayIsBeforeStartArray() throws Exception {
        thrown.expect(JsonException.class);
        jsonWriter.writeEndArray();
    }

    @Test
    public void failsWhenOneFollowsOther() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key1");

        thrown.expect(JsonException.class);
        jsonWriter.writeKey("key2");
    }

    @Test
    public void failsWhenKeyInsideArray() throws Exception {
        jsonWriter.writeStartArray();

        thrown.expect(JsonException.class);
        jsonWriter.writeKey("key");
    }

    @Test
    public void failsWhenKeyIsNull() throws Exception {
        jsonWriter.writeStartArray();

        thrown.expect(JsonException.class);
        jsonWriter.writeKey(null);
    }

    @Test
    public void failsWhenKeyIsEmpty() throws Exception {
        jsonWriter.writeStartArray();

        thrown.expect(JsonException.class);
        jsonWriter.writeKey("");
    }

    @Test
    public void failsWhenKeyContainsOnlySpaces() throws Exception {
        jsonWriter.writeStartArray();

        thrown.expect(JsonException.class);
        jsonWriter.writeKey("  ");
    }

    @Test
    public void writesStringValue() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeValue("value");
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":\"value\"}", writer.toString());
    }

    @Test
    public void writesLongValue() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeValue(777);
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":777}", writer.toString());
    }

    @Test
    public void writesDoubleValue() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeValue(7.77);
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":7.77}", writer.toString());
    }

    @Test
    public void writesBooleanValue() throws Exception {
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeValue(true);
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":true}", writer.toString());
    }

    @Test
    public void skipsNullValueByDefault() throws Exception {
        assertFalse(jsonWriter.isWriteNulls());
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key1");
        jsonWriter.writeNull();
        jsonWriter.writeKey("key2");
        jsonWriter.writeValue("value");
        jsonWriter.writeEndObject();

        assertEquals("{\"key2\":\"value\"}", writer.toString());
    }

    @Test
    public void writesNullValueWhenWritingNullsIsAllowed() throws Exception {
        jsonWriter.setWriteNulls(true);
        jsonWriter.writeStartObject();
        jsonWriter.writeKey("key");
        jsonWriter.writeNull();
        jsonWriter.writeKey("key2");
        jsonWriter.writeValue("value");
        jsonWriter.writeEndObject();

        assertEquals("{\"key\":null,\"key2\":\"value\"}", writer.toString());
    }

    @Test
    public void writesArrayOfValues() throws Exception {
        jsonWriter.writeStartArray();
        jsonWriter.writeValue("value1");
        jsonWriter.writeValue("value2");
        jsonWriter.writeEndArray();

        assertEquals("[\"value1\",\"value2\"]", writer.toString());
    }

    @Test
    public void failsWriteValueWhenItDoesNotFollowKeyOrIsNotItemOfArray() throws Exception {
        jsonWriter.writeStartObject();

        thrown.expect(JsonException.class);
        jsonWriter.writeValue("value");
    }

    @Test
    public void flushesUnderlyingWriter() throws Exception {
        Writer writer = mock(Writer.class);
        jsonWriter = new JsonWriter(writer);

        jsonWriter.flush();
        verify(writer).flush();
    }

    @Test
    public void closesUnderlyingWriter() throws Exception {
        Writer writer = mock(Writer.class);
        jsonWriter = new JsonWriter(writer);

        jsonWriter.close();
        verify(writer).close();
    }
}