org.zalando.github.spring.pagination.PaginationTest.java Source code

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Here is the source code for org.zalando.github.spring.pagination.PaginationTest.java

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/**
 * Copyright (C) 2015 Zalando SE (http://tech.zalando.com)
 *
 * 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 org.zalando.github.spring.pagination;

import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.assertj.core.api.Assertions;
import org.junit.Test;
import org.mockito.Mockito;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestOperations;

public class PaginationTest {

    private final ParameterizedTypeReference<List<String>> issueListTypeRef = new ParameterizedTypeReference<List<String>>() {
    };

    private final URI uri = URI.create("https://api.github.com/organizations/12345678/issues?per_page=1");

    private final String LINK_HEADER = "<https://api.github.com/organizations/12345678/issues?per_page=1&page=2>; rel=\"next\", <https://api.github.com/organizations/12345678/issues?per_page=1&page=3>; rel=\"last\"";
    private final String LINK_HEADER_2 = "<https://api.github.com/organizations/12345678/issues?per_page=1&page=3>; rel=\"next\", <https://api.github.com/organizations/12345678/issues?per_page=1&page=3>; rel=\"last\"";
    private final String LINK_HEADER_LAST = "<https://api.github.com/organizations/12345678/issues?per_page=3&page=2>; rel=\"prev\"";

    @SuppressWarnings("unchecked")
    @Test
    public void pagination() {

        RestOperations restOperations = Mockito.mock(RestOperations.class);

        ResponseEntity<List<String>> firstResponse = first();
        ResponseEntity<List<String>> secondResponse = second();
        ResponseEntity<List<String>> thirdResponse = third();

        Mockito.when(restOperations.exchange(Mockito.any(URI.class), Mockito.any(HttpMethod.class),
                Mockito.any(HttpEntity.class), Mockito.any(issueListTypeRef.getClass())))
                .thenReturn(firstResponse, secondResponse, thirdResponse);

        List<String> result = new ArrayList<>();
        PagingIterator<List<String>> iter = new PagingIterator(restOperations, uri, issueListTypeRef);
        while (iter.hasNext()) {
            List<String> next = iter.next();
            result.addAll(next);
        }
        Assertions.assertThat(result.isEmpty()).isFalse();
        Assertions.assertThat(result.size()).isEqualTo(3);
        Assertions.assertThat(result).contains("firstElement", "secondElement", "thirdElement");
    }

    protected ResponseEntity<List<String>> first() {
        ResponseEntity<List<String>> result = Mockito.mock(ResponseEntity.class);
        Mockito.when(result.getHeaders()).thenReturn(buildHeaders(LINK_HEADER));
        Mockito.when(result.getBody()).thenReturn(Collections.singletonList("firstElement"));
        return result;
    }

    protected ResponseEntity<List<String>> second() {
        ResponseEntity<List<String>> result = Mockito.mock(ResponseEntity.class);
        Mockito.when(result.getHeaders()).thenReturn(buildHeaders(LINK_HEADER_2));
        Mockito.when(result.getBody()).thenReturn(Collections.singletonList("secondElement"));
        return result;
    }

    protected ResponseEntity<List<String>> third() {
        ResponseEntity<List<String>> result = Mockito.mock(ResponseEntity.class);
        Mockito.when(result.getHeaders()).thenReturn(buildHeaders(LINK_HEADER_LAST));
        Mockito.when(result.getBody()).thenReturn(Collections.singletonList("thirdElement"));

        return result;
    }

    protected HttpHeaders buildHeaders(String headerValue) {
        HttpHeaders headers = new HttpHeaders();
        headers.add("Link", headerValue);
        return headers;
    }
}