Support excluding files matched by .gitignore across nohttp

nohttp-checkstyle/README.adoc

@@ -73,6 +73,22 @@ For example, the following will allowlist `http://example.com` and `http://examp
 NOTE: Use `&#10` to specify new lines.
 
 
+=== Excluding files matched by .gitignore
+
+By default, `NoHttpCheck` additionally excludes any file matched by a `.gitignore` file found in `baseDir` (which defaults to the current working directory), so that paths already ignored by git (build output, IDE metadata, etc.) don't need to be duplicated in your checkstyle configuration or `<excludes>`. This is especially useful for Maven and Ant users, since (unlike Gradle) there is no dedicated nohttp plugin to configure exclusions on - `NoHttpCheck` is wired up directly via `maven-checkstyle-plugin` or the Ant checkstyle task, so this is applied automatically.
+
+This can be disabled with the `useGitIgnore` property, and the directory that `.gitignore` is looked up from (and that paths are matched relative to) can be overridden with the `baseDir` property:
+
+[source,xml]
+----
+<module name="io.spring.nohttp.checkstyle.check.NoHttpCheck">
+	<property name="useGitIgnore" value="false"/>
+	<property name="baseDir" value="${basedir}" default=""/>
+</module>
+----
+
+NOTE: Only a single `.gitignore` file, at the root of `baseDir`, is considered; nested `.gitignore` files in subdirectories are not supported.
+
 === Suppress With Comments
 
 The above <<configuration>> demonstrates how to suppress checks using https://checkstyle.org/config_filters.html#SuppressWithPlainTextCommentFilter[SuppressWithPlainTextCommentFilter]. For example, the following will ignore the URL `http://example.org/schema/` only in the location of code surrounded by the `CHECKSTYLE:OFF` / `CHECKSTYLE:ON` comments.

nohttp-checkstyle/src/main/java/io/spring/nohttp/checkstyle/check/NoHttpCheck.java

@@ -21,6 +21,7 @@
 import com.puppycrawl.tools.checkstyle.api.ExternalResourceHolder;
 import com.puppycrawl.tools.checkstyle.api.FileText;
 import io.spring.nohttp.*;
+import io.spring.nohttp.file.GitIgnoreFileFilter;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
@@ -111,11 +112,46 @@
  * </module>
  * </pre>
  *
+ * <h2>useGitIgnore</h2>
+ *
+ * <p>
+ * By default, files matched by a {@code .gitignore} file found in {@code baseDir} are
+ * additionally excluded, so that paths already ignored by git (build output, IDE
+ * metadata, etc.) do not need to be duplicated in the checkstyle configuration. Set to
+ * {@code false} to disable.
+ * </p>
+ *
+ * <pre>
+ * &lt;module name="io.spring.nohttp.checkstyle.check.NoHttpCheck"&gt;
+ *     &lt;property name="useGitIgnore" value="false"/&gt;
+ * &lt;/module&gt;
+ * </pre>
+ *
+ * <h2>baseDir</h2>
+ *
+ * <p>
+ * The directory that a {@code .gitignore} file is looked up from, and that files are
+ * resolved relative to when matching {@code .gitignore} patterns. Defaults to the
+ * current working directory.
+ * </p>
+ *
+ * <pre>
+ * &lt;module name="io.spring.nohttp.checkstyle.check.NoHttpCheck"&gt;
+ *     &lt;property name="baseDir" value="${basedir}" default=""/&gt;
+ * &lt;/module&gt;
+ * </pre>
+ *
  * @author Rob Winch
  */
 public class NoHttpCheck extends AbstractFileSetCheck implements ExternalResourceHolder {
 	private HttpMatcher matcher;
 
+	private String baseDir = System.getProperty("user.dir");
+
+	private boolean useGitIgnore = true;
+
+	private GitIgnoreFileFilter gitIgnoreFilter;
+
 	private String allowlistFileName = "";
 
 	private String allowlist = "";
@@ -159,6 +195,29 @@ public void setWhitelist(String allowlist) {
 		setWhitelistFileName(allowlist);
 	}
 
+	/**
+	 * Sets the directory that a {@code .gitignore} file is looked up from, and that
+	 * files are resolved relative to when matching {@code .gitignore} patterns.
+	 * @param baseDir the base directory to use
+	 * @since 0.0.12
+	 */
+	public void setBaseDir(String baseDir) {
+		if (baseDir == null) {
+			throw new IllegalArgumentException("baseDir cannot be null");
+		}
+		this.baseDir = baseDir;
+	}
+
+	/**
+	 * Sets whether files matched by a {@code .gitignore} file found in {@link
+	 * #setBaseDir(String) baseDir} should additionally be excluded.
+	 * @param useGitIgnore true to exclude files matched by {@code .gitignore}
+	 * @since 0.0.12
+	 */
+	public void setUseGitIgnore(boolean useGitIgnore) {
+		this.useGitIgnore = useGitIgnore;
+	}
+
 	private boolean isAllowlistFileSet() {
 		return !this.allowlistFileName.isEmpty();
 	}
@@ -190,11 +249,17 @@ protected void finishLocalSetup() throws CheckstyleException {
 			matcher.addHttpAllow(RegexPredicate.createAllowlistFromPatterns(inputStream));
 		}
 		this.matcher = matcher;
+
+		this.gitIgnoreFilter = this.useGitIgnore ?
+				GitIgnoreFileFilter.forBaseDir(new File(this.baseDir)).orElse(null) : null;
 	}
 
 	@Override
 	protected void processFiltered(File file, FileText fileText)
 			throws CheckstyleException {
+		if (this.gitIgnoreFilter != null && this.gitIgnoreFilter.test(file)) {
+			return;
+		}
 		int lineNum = 0;
 		for (int index = 0; index < fileText.size(); index++) {
 			final String line = fileText.get(index);
@@ -212,6 +277,12 @@ public Set<String> getExternalResourceLocations() {
 		if (isAllowlistFileSet()) {
 			result.add(this.allowlistFileName);
 		}
+		if (this.useGitIgnore) {
+			File gitignore = new File(this.baseDir, ".gitignore");
+			if (gitignore.isFile()) {
+				result.add(gitignore.getPath());
+			}
+		}
 		return result;
 	}
 }

nohttp-checkstyle/src/test/java/io/spring/nohttp/checkstyle/check/NoHttpCheckTest.java

@@ -16,7 +16,16 @@
 
 package io.spring.nohttp.checkstyle.check;
 
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.api.FileText;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 
 import static org.assertj.core.api.Assertions.*;
 
@@ -25,6 +34,9 @@
  */
 public class NoHttpCheckTest {
 
+	@Rule
+	public TemporaryFolder temp = new TemporaryFolder();
+
 	private NoHttpCheck check = new NoHttpCheck();
 
 	@Test
@@ -42,14 +54,100 @@ public void setAllowlistWhenNullThenIllegalArgumentException() {
 	}
 
 	@Test
-	public void getExternalResourceLocationsWhenNoAllowlistlistThenEmpty() {
+	public void setBaseDirWhenNullThenIllegalArgumentException() {
+		assertThatCode(() -> this.check.setBaseDir(null))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessage("baseDir cannot be null");
+	}
+
+	@Test
+	public void getExternalResourceLocationsWhenNoAllowlistlistThenEmpty() throws IOException {
+		this.check.setBaseDir(this.temp.newFolder().getPath());
 		assertThat(this.check.getExternalResourceLocations()).isEmpty();
 	}
 
 	@Test
-	public void getExternalResourceLocationsWhenAllowlistlistThenEmpty() {
+	public void getExternalResourceLocationsWhenAllowlistlistThenEmpty() throws IOException {
+		this.check.setBaseDir(this.temp.newFolder().getPath());
 		String allowlistFileName = "allowlist.lines";
 		this.check.setAllowlistFileName(allowlistFileName);
 		assertThat(this.check.getExternalResourceLocations()).containsOnly(allowlistFileName);
 	}
+
+	@Test
+	public void getExternalResourceLocationsWhenGitIgnoreThenIncludesGitIgnore() throws IOException {
+		File baseDir = this.temp.newFolder();
+		File gitignore = writeGitignore(baseDir);
+		this.check.setBaseDir(baseDir.getPath());
+
+		assertThat(this.check.getExternalResourceLocations()).containsOnly(gitignore.getPath());
+	}
+
+	@Test
+	public void getExternalResourceLocationsWhenGitIgnoreAndUseGitIgnoreDisabledThenEmpty() throws IOException {
+		File baseDir = this.temp.newFolder();
+		writeGitignore(baseDir);
+		this.check.setBaseDir(baseDir.getPath());
+		this.check.setUseGitIgnore(false);
+
+		assertThat(this.check.getExternalResourceLocations()).isEmpty();
+	}
+
+	@Test
+	public void processWhenGitIgnoredThenNoViolationsLogged() throws Exception {
+		File baseDir = this.temp.newFolder();
+		writeGitignore(baseDir, "ignored.txt");
+		File file = newFile(baseDir, "ignored.txt", "http://example.com");
+		this.check.setBaseDir(baseDir.getPath());
+		this.check.configure(new DefaultConfiguration("NoHttpCheck"));
+
+		assertThat(this.check.process(file, fileTextFor(file))).isEmpty();
+	}
+
+	@Test
+	public void processWhenNotGitIgnoredThenViolationsLogged() throws Exception {
+		File baseDir = this.temp.newFolder();
+		writeGitignore(baseDir, "ignored.txt");
+		File file = newFile(baseDir, "found.txt", "http://example.com");
+		this.check.setBaseDir(baseDir.getPath());
+		this.check.configure(new DefaultConfiguration("NoHttpCheck"));
+
+		assertThat(this.check.process(file, fileTextFor(file))).isNotEmpty();
+	}
+
+	@Test
+	public void processWhenGitIgnoredAndUseGitIgnoreDisabledThenViolationsLogged() throws Exception {
+		File baseDir = this.temp.newFolder();
+		writeGitignore(baseDir, "ignored.txt");
+		File file = newFile(baseDir, "ignored.txt", "http://example.com");
+		this.check.setBaseDir(baseDir.getPath());
+		this.check.setUseGitIgnore(false);
+		this.check.configure(new DefaultConfiguration("NoHttpCheck"));
+
+		assertThat(this.check.process(file, fileTextFor(file))).isNotEmpty();
+	}
+
+	private static FileText fileTextFor(File file) throws IOException {
+		return new FileText(file, StandardCharsets.UTF_8.name());
+	}
+
+	private static File writeGitignore(File baseDir, String... patterns) throws IOException {
+		File gitignore = new File(baseDir, ".gitignore");
+		StringBuilder content = new StringBuilder();
+		for (String pattern : patterns) {
+			content.append(pattern).append('\n');
+		}
+		if (patterns.length == 0) {
+			content.append("*.log\n");
+		}
+		Files.write(gitignore.toPath(), content.toString().getBytes());
+		return gitignore;
+	}
+
+	private static File newFile(File baseDir, String relativePath, String content) throws IOException {
+		File file = new File(baseDir, relativePath);
+		file.getParentFile().mkdirs();
+		Files.write(file.toPath(), content.getBytes());
+		return file;
+	}
 }

nohttp-cli/README.adoc

@@ -50,7 +50,8 @@ Keep in mind this may delete things you want (i.e. IDE related files).
 === Hello nohttp
 
 The easiest approach is to run the application with no arguments.
-This will attempt to find http in all text based files in the current directory while ignoring `.git` folder.
+This will attempt to find http in all text based files in the current directory while ignoring the `.git` folder.
+If a `.gitignore` file exists at the root of the scanned directory, files it matches are excluded as well; use the `-g` flag shown in <<help,Help>> to disable this.
 
 [NOTE]
 ====
@@ -84,7 +85,7 @@ You can get help with additional options using `--help`.
 ----
 java -jar $NOHTTP --help
 ...
-Usage: nohttp [-fhMrsTV] [-w=<allowlistFile>] [-D=<regex>]... [-F=<regex>]...
+Usage: nohttp [-fghMrsTV] [-w=<allowlistFile>] [-D=<regex>]... [-F=<regex>]...
               [<dir>]
       [<dir>]           The directory to scan. Default is current working directory.
   -D=<regex>            Regular expression of directories to exclude scanning.
@@ -94,6 +95,8 @@ Usage: nohttp [-fhMrsTV] [-w=<allowlistFile>] [-D=<regex>]... [-F=<regex>]...
   -F=<regex>            Regular expression of files to exclude scanning. Specify
                           multiple times to provide multiple exclusions. Default is
                           no file exclusions.
+  -g                    Disable additionally excluding files matched by a .gitignore
+                          file found at the root of the scanned directory.
   -h, --help            Show this help message and exit.
   -M                    Disables printing each match within their specific files.
   -r                    Enables replacing the values that were found. The default is

nohttp-cli/build.gradle

@@ -29,6 +29,8 @@ repositories {
 dependencies {
 	compile project(':nohttp')
 	compile 'info.picocli:picocli:3.9.5'
+	testCompile 'junit:junit'
+	testCompile 'org.assertj:assertj-core'
 }
 
 shadowJar {

nohttp-cli/src/main/java/io/spring/nohttp/cli/ReplaceFilesRunner.java

@@ -24,6 +24,7 @@
 import io.spring.nohttp.RegexPredicate;
 import io.spring.nohttp.StatusHttpReplacer;
 import io.spring.nohttp.file.DirScanner;
+import io.spring.nohttp.file.GitIgnoreFileFilter;
 import io.spring.nohttp.file.PreGradle21Scanner;
 import io.spring.nohttp.file.HttpMatcherProcessor;
 import io.spring.nohttp.file.HttpReplacerProcessor;
@@ -68,6 +69,9 @@ public class ReplaceFilesRunner implements Callable<Integer> {
 	@CommandLine.Option(names = "-F", paramLabel = "<regex>", description = "Regular expression of files to exclude scanning. Specify multiple times to provide multiple exclusions. Default is no file exclusions.")
 	private List<Pattern> fileExclusions = new ArrayList<>();
 
+	@CommandLine.Option(names = "-g", description = "Disable additionally excluding files matched by a .gitignore file found at the root of the scanned directory.", defaultValue = "true")
+	private boolean gitIgnore = true;
+
 	@CommandLine.Option(names = "-M", description = "Disables printing each match within their specific files.", defaultValue = "false")
 	private boolean disablePrintMatches;
 
@@ -98,11 +102,17 @@ public Integer call() throws Exception {
 
 		System.out.println();
 		System.out.println("Looking for restricted http:// URLs");
-		DirScanner.create(this.dir)
+		DirScanner scanner = DirScanner.create(this.dir)
 			.textFiles(this.textFilesOnly)
 			.excludeDirs(dirExclusions())
-			.excludeFiles(fileExclusions())
-			.scan(withHttpProcessor(processor));
+			.excludeFiles(fileExclusions());
+		if (this.gitIgnore) {
+			GitIgnoreFileFilter.forBaseDir(this.dir).ifPresent(filter -> {
+				scanner.excludeDirs(filter);
+				scanner.excludeFiles(filter);
+			});
+		}
+		scanner.scan(withHttpProcessor(processor));
 
 		Set<String> httpUrlMatches = processor.getHttpMatches();
 		writeSummaryReport(httpUrlMatches);