#36 Extract network side effect into interface so we can mock this out in the tests

Signed-off-by: Sven Strittmatter <sven.strittmatter@iteratec.com>

Author: Weltraumschaf

src/main/java/io/securecodebox/persistence/defectdojo/service/DefaultImportScanService.java

@@ -45,7 +45,7 @@ class DefaultImportScanService implements ImportScanService {
         new FormHttpMessageConverter(),
         new ResourceHttpMessageConverter(),
         new MappingJackson2HttpMessageConverter());
-    private final SystemPropertyFinder properties = new SystemPropertyFinder();
+    private final HttpRequester requester = new DefaultHttpRequester();
     @Getter
     private final String defectDojoUrl;
     @Getter
@@ -115,31 +115,17 @@ public String getFilename() {
                 }
             };
 
-            // FIXME: Why do we add the whole byte array resiurce here as object? Is not simply the file name sufficient here? Then we could use <String, String>
+            // FIXME: Why do we add the whole byte array resource here as object? Is not simply the file name sufficient here? Then we could use <String, String>
             // We send the whole file content, so DefectDojo can parse the finding by itself.
             body.add("file", contentsAsResource);
 
             final var payload = new HttpEntity<MultiValueMap<String, Object>>(body, headers);
-            return exchangeRequest(endpoint, payload);
+            return requester.exchange(generateApiUrl(endpoint), payload);
         } catch (HttpClientErrorException e) {
             throw new DefectDojoPersistenceException("Failed to attach findings to engagement.");
         }
     }
 
-    ImportScanResponse exchangeRequest(String endpoint, HttpEntity<?> payload) {
-        final var restTemplate = this.createRestTemplate();
-        return restTemplate.exchange(
-                generateApiUrl(endpoint),
-                HttpMethod.POST,
-                payload,
-                ImportScanResponse.class)
-            .getBody();
-    }
-
-    String generateApiUrl(final String endpoint) {
-        return String.format("%s/api/v2/%s/", getDefectDojoUrl(), endpoint);
-    }
-
     /**
      * The DefectDojo Authentication Header
      *
@@ -151,104 +137,133 @@ HttpHeaders createDefectDojoAuthorizationHeaders() {
         return authorizationHeader;
     }
 
-    private RestTemplate createRestTemplate() {
-        final var template = new RestTemplate();
+    String generateApiUrl(final String endpoint) {
+        return String.format("%s/api/v2/%s/", getDefectDojoUrl(), endpoint);
+    }
 
-        if (shouldConfigureProxySettings()) {
-            template.setRequestFactory(createRequestFactoryWithProxyAuthConfig());
+    private static class SystemPropertyFinder {
+        private boolean hasProperty(@NonNull final ProxyConfigNames name) {
+            return System.getProperty(name.getLiterat()) != null;
         }
 
-        template.setMessageConverters(HTTP_MESSAGE_CONVERTERS);
+        private boolean notHasProperty(@NonNull final ProxyConfigNames name) {
+            return !hasProperty(name);
+        }
 
-        return template;
+        private String getProperty(@NonNull final ProxyConfigNames name) {
+            return System.getProperty(name.getLiterat());
+        }
     }
 
-    boolean shouldConfigureProxySettings() {
-        return properties.hasProperty(ProxyConfigNames.HTTP_PROXY_USER)
-            && properties.hasProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD);
+    final static class MissingProxyAuthenticationConfig extends RuntimeException {
+        MissingProxyAuthenticationConfig(ProxyConfigNames name) {
+            super(String.format("Expected System property '%s' not set!", name.getLiterat()));
+        }
     }
 
     /**
-     * Configuring proxy authentication explicitly
-     *
-     * <p>
-     * This isn't done by default for spring rest templates.This method expects these four system properties (Java flag
-     * {@literal -DpropertyName}) to be set:
-     * </p>
-     * <ul>
-     *     <li>http.proxyUser</li>
-     *     <li>http.proxyPassword</li>
-     *     <li>http.proxyHost</li>
-     *     <li>http.proxyPort</li>
-     * </ul>
-     *
-     * @return never {@code null}
+     * This interface abstracts the network side effect done by the underlying HTTP
      */
-    ClientHttpRequestFactory createRequestFactoryWithProxyAuthConfig() {
-        if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_USER)) {
-            throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_USER);
-        }
-
-        if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD)) {
-            throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_PASSWORD);
-        }
-
-        if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_HOST)) {
-            throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_HOST);
-        }
+    interface HttpRequester {
+        ImportScanResponse exchange(String endpoint, HttpEntity<?> payload);
+    }
 
-        if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_PORT)) {
-            throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_PORT);
+    /**
+     * Default implementation which utilizes {@link RestTemplate}
+     */
+    static final class DefaultHttpRequester implements HttpRequester {
+        private final SystemPropertyFinder properties = new SystemPropertyFinder();
+
+        @Override
+        public ImportScanResponse exchange(final String url, final HttpEntity<?> payload) {
+            final var restTemplate = this.createRestTemplate();
+            return restTemplate.exchange(
+                    url,
+                    HttpMethod.POST,
+                    payload,
+                    ImportScanResponse.class)
+                .getBody();
         }
 
-        final var proxyHost = properties.getProperty(ProxyConfigNames.HTTP_PROXY_HOST);
-        final int proxyPort;
-        try {
-            proxyPort = Integer.parseInt(properties.getProperty(ProxyConfigNames.HTTP_PROXY_PORT));
-        } catch (final NumberFormatException e) {
-            throw new IllegalArgumentException(
-                String.format("Given port for proxy authentication configuration (property '%s') is not a valid number! Given value wa '%s'.",
-                    ProxyConfigNames.HTTP_PROXY_PORT.getLiterat(),
-                    System.getProperty("http.proxyPort")),
-                e);
-        }
+        private RestTemplate createRestTemplate() {
+            final var template = new RestTemplate();
 
-        final var credentials = new BasicCredentialsProvider();
-        credentials.setCredentials(
-            new AuthScope(proxyHost, proxyPort),
-            new UsernamePasswordCredentials(
-                properties.getProperty(ProxyConfigNames.HTTP_PROXY_USER),
-                properties.getProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD))
-        );
-
-        final var clientBuilder = HttpClientBuilder.create();
-        clientBuilder.useSystemProperties();
-        clientBuilder.setProxy(new HttpHost(proxyHost, proxyPort));
-        clientBuilder.setDefaultCredentialsProvider(credentials);
-        clientBuilder.setProxyAuthenticationStrategy(new ProxyAuthenticationStrategy());
-
-        final var factory = new HttpComponentsClientHttpRequestFactory();
-        factory.setHttpClient(clientBuilder.build());
-        return factory;
-    }
+            if (shouldConfigureProxySettings()) {
+                template.setRequestFactory(createRequestFactoryWithProxyAuthConfig());
+            }
 
-    private static class SystemPropertyFinder {
-        private boolean hasProperty(@NonNull final ProxyConfigNames name) {
-            return System.getProperty(name.getLiterat()) != null;
-        }
+            template.setMessageConverters(HTTP_MESSAGE_CONVERTERS);
 
-        private boolean notHasProperty(@NonNull final ProxyConfigNames name) {
-            return !hasProperty(name);
+            return template;
         }
 
-        private String getProperty(@NonNull final ProxyConfigNames name) {
-            return System.getProperty(name.getLiterat());
+        boolean shouldConfigureProxySettings() {
+            return properties.hasProperty(ProxyConfigNames.HTTP_PROXY_USER)
+                && properties.hasProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD);
         }
-    }
 
-    final static class MissingProxyAuthenticationConfig extends RuntimeException {
-        MissingProxyAuthenticationConfig(ProxyConfigNames name) {
-            super(String.format("Expected System property '%s' not set!", name.getLiterat()));
+        /**
+         * Configuring proxy authentication explicitly
+         *
+         * <p>
+         * This isn't done by default for spring rest templates.This method expects these four system properties (Java flag
+         * {@literal -DpropertyName}) to be set:
+         * </p>
+         * <ul>
+         *     <li>http.proxyUser</li>
+         *     <li>http.proxyPassword</li>
+         *     <li>http.proxyHost</li>
+         *     <li>http.proxyPort</li>
+         * </ul>
+         *
+         * @return never {@code null}
+         */
+        ClientHttpRequestFactory createRequestFactoryWithProxyAuthConfig() {
+            if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_USER)) {
+                throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_USER);
+            }
+
+            if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD)) {
+                throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_PASSWORD);
+            }
+
+            if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_HOST)) {
+                throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_HOST);
+            }
+
+            if (properties.notHasProperty(ProxyConfigNames.HTTP_PROXY_PORT)) {
+                throw new MissingProxyAuthenticationConfig(ProxyConfigNames.HTTP_PROXY_PORT);
+            }
+
+            final var proxyHost = properties.getProperty(ProxyConfigNames.HTTP_PROXY_HOST);
+            final int proxyPort;
+            try {
+                proxyPort = Integer.parseInt(properties.getProperty(ProxyConfigNames.HTTP_PROXY_PORT));
+            } catch (final NumberFormatException e) {
+                throw new IllegalArgumentException(
+                    String.format("Given port for proxy authentication configuration (property '%s') is not a valid number! Given value wa '%s'.",
+                        ProxyConfigNames.HTTP_PROXY_PORT.getLiterat(),
+                        System.getProperty("http.proxyPort")),
+                    e);
+            }
+
+            final var credentials = new BasicCredentialsProvider();
+            credentials.setCredentials(
+                new AuthScope(proxyHost, proxyPort),
+                new UsernamePasswordCredentials(
+                    properties.getProperty(ProxyConfigNames.HTTP_PROXY_USER),
+                    properties.getProperty(ProxyConfigNames.HTTP_PROXY_PASSWORD))
+            );
+
+            final var clientBuilder = HttpClientBuilder.create();
+            clientBuilder.useSystemProperties();
+            clientBuilder.setProxy(new HttpHost(proxyHost, proxyPort));
+            clientBuilder.setDefaultCredentialsProvider(credentials);
+            clientBuilder.setProxyAuthenticationStrategy(new ProxyAuthenticationStrategy());
+
+            final var factory = new HttpComponentsClientHttpRequestFactory();
+            factory.setHttpClient(clientBuilder.build());
+            return factory;
         }
     }
 }