File filtering implementation a'la .gitignore

platform/lang-api/src/com/intellij/formatting/fileSet/FileSetEntry.java

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+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.formatting.fileSet;
+
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.VirtualFile;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.regex.Pattern;
+
+/**
+ * Describes a set of files specified by a directory and/or by a file mask.
+ * <p>
+ * Examples:
+ * <ul>
+ *   <li>
+ *     {@code *.test}<br>
+ *       A file ending with .test in any directory
+ *   </li>
+ *   <li>
+ *     {@code /foo/*.test}<br>
+ *       A file with *.test extension immediately under <i>project-dir</i>/foo directory.
+ *   </li>
+ *   <li>
+ *     {@code foo/*.test}<br>
+ *     A file with .test extension if their parent directory is "foo", equivalent to &#47;**&#47;foo&#47;*.test
+ *   </li>
+ *   <li>
+ *     {@code /*.test}
+ *     A file with .test extension directly under project root directory.
+ *   </li>
+ * </ul>
+ */
+public class FileSetEntry {
+
+  private @Nullable Pattern myPathPattern;
+  private @Nullable Pattern myFileNamePattern;
+
+  public FileSetEntry(@NotNull String spec) {
+    compileSpec(spec);
+  }
+
+  private void compileSpec(@NotNull String spec) {
+    String pathSpec = "";
+    String fileSpec;
+    int lastSlashPos = spec.lastIndexOf('/');
+    if (lastSlashPos >= 0) {
+      fileSpec = spec.substring(lastSlashPos + 1);
+      pathSpec = spec.substring(0, lastSlashPos + 1);
+      if (pathSpec.length() > 0 && pathSpec.charAt(0) != '/') {
+        pathSpec = "/**/" + pathSpec;
+      }
+    }
+    else {
+      fileSpec = spec;
+    }
+    if (!pathSpec.isEmpty()) {
+      myPathPattern = Pattern.compile(specToRegexp(pathSpec, true));
+    }
+    if (!fileSpec.isEmpty()) {
+      myFileNamePattern = Pattern.compile(specToRegexp(fileSpec, false));
+    }
+  }
+
+  private static String specToRegexp(@NotNull String spec, boolean isPathSpec) {
+    StringBuilder sb = new StringBuilder();
+    char[] chars = spec.toCharArray();
+    int i = 0;
+    while (i < chars.length) {
+      char c = chars[i];
+      switch (c) {
+        case '*':
+          if (isPathSpec && i < chars.length - 1 && chars[i + 1] == '*') {
+            sb.append("([^/]*/)*");
+            i++;
+            if (i < chars.length - 1 && chars[i + 1] == '/') {
+              i ++;
+            }
+          }
+          else {
+            sb.append("[^/]*");
+          }
+          break;
+        case '?':
+          sb.append("[^/]");
+          break;
+        default:
+          if (isRegexSpecialChar(c)) {
+            sb.append('\\').append(c);
+          }
+          else {
+            sb.append(c);
+          }
+      }
+      i ++;
+    }
+    return sb.toString();
+  }
+
+
+  private static boolean isRegexSpecialChar(char c) {
+    return "^${}[]().*+-&".indexOf(c) >= 0;
+  }
+
+  /**
+   * Checks if the file set entry matches the given virtual file.
+   *
+   * @param project     The current project.
+   * @param virtualFile The virtual file to check against.
+   * @return True if there is a match, false otherwise.
+   */
+  public boolean matches(@NotNull Project project, @NotNull VirtualFile virtualFile) {
+    if (myFileNamePattern == null && myPathPattern == null) return false; // Empty spec matches nothing
+    String name = virtualFile.getName();
+    VirtualFile parent = virtualFile.getParent();
+    String path = getRelativePath(project, parent) + "/";
+    return patternMatches(myPathPattern, path) && patternMatches(myFileNamePattern, name);
+  }
+
+  @NotNull
+  private static String getRelativePath(@NotNull Project project, @Nullable VirtualFile parent) {
+    VirtualFile projectDir = project.getBaseDir();
+    String projectPath = projectDir.getPath();
+    if (parent != null) {
+      String parentPath = parent.getPath();
+      if (parentPath.startsWith(projectPath)) {
+        return parentPath.substring(projectPath.length());
+      }
+      else {
+        return parentPath;
+      }
+    }
+    return "";
+  }
+
+  private static boolean patternMatches(@Nullable Pattern pattern, @NotNull String str) {
+    return pattern == null || pattern.matcher(str).matches();
+  }
+}

platform/platform-tests/testSrc/com/intellij/formatting/fileSet/FileSetEntryTest.java

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+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.formatting.fileSet;
+
+import com.intellij.openapi.vfs.VfsUtilCore;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.testFramework.PlatformTestCase;
+import org.jetbrains.annotations.NotNull;
+
+public class FileSetEntryTest extends PlatformTestCase {
+
+  public void testSimpleFileMask() {
+    FileSetEntry entry = new FileSetEntry("*.java");
+    assertTrue(entry.matches(getProject(), createFile("src/test.java")));
+    assertFalse(entry.matches(getProject(), createFile("src/test.txt")));
+    assertTrue(entry.matches(getProject(), createFile("file3.java")));
+  }
+
+  public void testFileMaskWithDir() {
+    FileSetEntry entry = new FileSetEntry("/src/*.java");
+    assertTrue(entry.matches(getProject(), createFile("src/test.java")));
+    assertFalse(entry.matches(getProject(), createFile("src/test.txt")));
+    assertFalse(entry.matches(getProject(), createFile("file3.java")));
+  }
+
+  public void testExtendedDirSpec() {
+    FileSetEntry entry = new FileSetEntry("/src/**/test/*.java");
+    assertTrue(entry.matches(getProject(), createFile("src/test/file1.java")));
+    assertTrue(entry.matches(getProject(), createFile("src/dir1/test/file1.java")));
+    assertTrue(entry.matches(getProject(), createFile("src/dir1/dir2/test/file1.java")));
+    assertFalse(entry.matches(getProject(), createFile("src/dir1/dir2/test/dir3/file1.java")));
+    FileSetEntry entry2 = new FileSetEntry("/src/**/test/**/*.java");
+    assertTrue(entry2.matches(getProject(), createFile("src/test/a/file1.java")));
+    assertTrue(entry2.matches(getProject(), createFile("src/b/test/a/file1.java")));
+  }
+
+  public void testAnyCharMarks() {
+    FileSetEntry entry = new FileSetEntry("/test-??/**/test?.java");
+    assertFalse(entry.matches(getProject(), createFile("test-1/test2.java")));
+    assertTrue(entry.matches(getProject(), createFile("test-12/test3.java")));
+    assertTrue(entry.matches(getProject(), createFile("test-12/test/testa.java")));
+  }
+
+
+  public void testRelativeDirTest() {
+    FileSetEntry entry = new FileSetEntry("test/*.java");
+    assertTrue(entry.matches(getProject(), createFile("src/test/file1.java")));
+    assertTrue(entry.matches(getProject(), createFile("test/file2.java")));
+    assertTrue(entry.matches(getProject(), createFile("a/b/c/d/test/file3.java")));
+  }
+
+  private VirtualFile createFile(@NotNull String path) {
+    String[] dirNames = path.split("/");
+    VirtualFile baseDir = getProject().getBaseDir();
+    for (int i = 0; i < dirNames.length - 1; i ++) {
+      VirtualFile existing = VfsUtilCore.findRelativeFile(dirNames[i], baseDir);
+      if (existing == null) {
+        baseDir = createChildDirectory(baseDir, dirNames[i]);
+      }
+      else {
+        baseDir = existing;
+      }
+    }
+    return createChildData(baseDir, dirNames[dirNames.length - 1]);
+  }
+
+}