Exclude minified files (#93)

4 files changed, 122 insertions, 2 deletions

diff --git a/sonar-css-plugin/src/main/java/org/sonar/css/plugin/CssPlugin.java b/sonar-css-plugin/src/main/java/org/sonar/css/plugin/CssPlugin.java
index cd98f25..5300947 100644
--- a/sonar-css-plugin/src/main/java/org/sonar/css/plugin/CssPlugin.java
+++ b/sonar-css-plugin/src/main/java/org/sonar/css/plugin/CssPlugin.java
@@ -53,6 +53,7 @@ public class CssPlugin implements Plugin {
       CssRuleSensor.class,
       StylelintCommandProvider.class,
       StylelintReportSensor.class,
+      MinifiedFilesFilter.class,
 
       PropertyDefinition.builder(FILE_SUFFIXES_KEY)
         .defaultValue(FILE_SUFFIXES_DEFVALUE)
diff --git a/sonar-css-plugin/src/main/java/org/sonar/css/plugin/MinifiedFilesFilter.java b/sonar-css-plugin/src/main/java/org/sonar/css/plugin/MinifiedFilesFilter.java
new file mode 100644
index 0000000..87dff1a
--- /dev/null
+++ b/sonar-css-plugin/src/main/java/org/sonar/css/plugin/MinifiedFilesFilter.java
@@ -0,0 +1,62 @@
+/*
+ * SonarCSS
+ * Copyright (C) 2018-2018 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.css.plugin;
+
+import java.io.IOException;
+import org.sonar.api.batch.fs.InputFile;
+import org.sonar.api.batch.fs.InputFileFilter;
+import org.sonar.api.utils.log.Logger;
+import org.sonar.api.utils.log.Loggers;
+
+public class MinifiedFilesFilter implements InputFileFilter {
+
+  private static final int AVERAGE_LINE_LENGTH_THRESHOLD = 200;
+
+  private static final Logger LOG = Loggers.get(MinifiedFilesFilter.class);
+
+  @Override
+  public boolean accept(InputFile file) {
+    if (!CssLanguage.KEY.equals(file.language())) {
+      return true;
+    }
+
+    try {
+      boolean isMinified = hasMinifiedFileName(file) || hasExcessiveAverageLineLength(file);
+      if (isMinified) {
+        LOG.debug("File [" + file.uri() + "] looks like a minified file and will not be analyzed");
+      }
+      return !isMinified;
+
+    } catch (IOException e) {
+      throw new IllegalStateException("Failed to read input file", e);
+    }
+  }
+
+  private static boolean hasMinifiedFileName(InputFile file) {
+    String fileName = file.filename();
+    return fileName.endsWith("-min.css") || fileName.endsWith(".min.css");
+  }
+
+  private static boolean hasExcessiveAverageLineLength(InputFile file) throws IOException {
+    int averageLineLength = file.contents().length() / file.lines();
+    return averageLineLength > AVERAGE_LINE_LENGTH_THRESHOLD;
+  }
+
+}
diff --git a/sonar-css-plugin/src/test/java/org/sonar/css/plugin/CssPluginTest.java b/sonar-css-plugin/src/test/java/org/sonar/css/plugin/CssPluginTest.java
index 7dfe16b..21a944a 100644
--- a/sonar-css-plugin/src/test/java/org/sonar/css/plugin/CssPluginTest.java
+++ b/sonar-css-plugin/src/test/java/org/sonar/css/plugin/CssPluginTest.java
@@ -36,7 +36,7 @@ public class CssPluginTest {
     Plugin.Context context = new Plugin.Context(runtime);
     Plugin underTest = new CssPlugin();
     underTest.define(context);
-    assertThat(context.getExtensions()).hasSize(10);
+    assertThat(context.getExtensions()).hasSize(11);
   }
 
   @Test
@@ -45,6 +45,6 @@ public class CssPluginTest {
     Plugin.Context context = new Plugin.Context(runtime);
     Plugin underTest = new CssPlugin();
     underTest.define(context);
-    assertThat(context.getExtensions()).hasSize(11);
+    assertThat(context.getExtensions()).hasSize(12);
   }
 }
diff --git a/sonar-css-plugin/src/test/java/org/sonar/css/plugin/MinifiedFilesFilterTest.java b/sonar-css-plugin/src/test/java/org/sonar/css/plugin/MinifiedFilesFilterTest.java
new file mode 100644
index 0000000..fc069e8
--- /dev/null
+++ b/sonar-css-plugin/src/test/java/org/sonar/css/plugin/MinifiedFilesFilterTest.java
@@ -0,0 +1,57 @@
+/*
+ * SonarCSS
+ * Copyright (C) 2018-2018 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.css.plugin;
+
+import org.junit.Test;
+import org.sonar.api.batch.fs.internal.DefaultInputFile;
+import org.sonar.api.batch.fs.internal.TestInputFileBuilder;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class MinifiedFilesFilterTest {
+
+  private static final MinifiedFilesFilter MINIFIED_FILES_FILTER = new MinifiedFilesFilter();
+
+  @Test
+  public void should_exclude_by_name() throws Exception {
+    DefaultInputFile jsFile = TestInputFileBuilder.create("", "foo.min.css")
+      .setLanguage("css")
+      .setContents("short content")
+      .build();
+    assertThat(MINIFIED_FILES_FILTER.accept(jsFile)).isFalse();
+  }
+
+  @Test
+  public void should_keep_other_lang() throws Exception {
+    DefaultInputFile jsFile = TestInputFileBuilder.create("", "foo.min.css").setLanguage("js").build();
+    assertThat(MINIFIED_FILES_FILTER.accept(jsFile)).isTrue();
+  }
+
+  @Test
+  public void should_exclude_by_content() throws Exception {
+    String longContent = new String(new char[500]).replace("\0", "a") + "\n";
+
+    DefaultInputFile jsFile = TestInputFileBuilder.create("", "foo.css")
+      .setLanguage("css")
+      .setContents(longContent)
+      .build();
+    assertThat(MINIFIED_FILES_FILTER.accept(jsFile)).isFalse();
+  }
+}