Add special case support for single line generated java files to the …

…package statement parser.

Since the parser is also used for generated source files in some cases, we can't assume that the input is a "normal" source file with a package statement on a line by itself. Generated source files sometimes have the entire content on a single line, so add support for that.

We do it this way to avoid using a full java parser which add extra complexity (though maybe not too much?).

PiperOrigin-RevId: 585650766

querysync/BUILD

@@ -29,6 +29,7 @@ test_suite(
         "//querysync/javatests/com/google/idea/blaze/qsync:AffectedPackagesTest",
         "//querysync/javatests/com/google/idea/blaze/qsync:GeneratedSourceProjectUpdaterTest",
         "//querysync/javatests/com/google/idea/blaze/qsync:GraphToProjectConverterTest",
+        "//querysync/javatests/com/google/idea/blaze/qsync:PackageStatementParserTest",
         "//querysync/javatests/com/google/idea/blaze/qsync:PartialProjectRefreshTest",
         "//querysync/javatests/com/google/idea/blaze/qsync:ProjectRefresherTest",
         "//querysync/javatests/com/google/idea/blaze/qsync:QuerySyncTestUtilsTest",

querysync/java/com/google/idea/blaze/qsync/PackageStatementParser.java

@@ -30,6 +30,8 @@
 public class PackageStatementParser implements PackageReader {
 
   private static final Pattern PACKAGE_PATTERN = Pattern.compile("^\\s*package\\s+([\\w\\.]+)");
+  private static final Pattern SINGLE_LINE_PACKAGE_PATTERN =
+      Pattern.compile("\\bpackage\\s+([^;]+);");
 
   @Override
   public String readPackage(Path path) throws IOException {
@@ -40,13 +42,26 @@ public String readPackage(Path path) throws IOException {
 
   public String readPackage(InputStream in) throws IOException {
     BufferedReader javaReader = new BufferedReader(new InputStreamReader(in, UTF_8));
+    String firstLine = null;
     String javaLine;
+    int linesRead = 0;
     while ((javaLine = javaReader.readLine()) != null) {
+      if (firstLine == null) {
+        firstLine = javaLine;
+      }
+      linesRead++;
       Matcher packageMatch = PACKAGE_PATTERN.matcher(javaLine);
       if (packageMatch.find()) {
         return packageMatch.group(1);
       }
     }
+    // A special case for generated sources files with no newlines in them:
+    if (linesRead == 1) {
+      Matcher packageMatch = SINGLE_LINE_PACKAGE_PATTERN.matcher(firstLine);
+      if (packageMatch.find()) {
+        return packageMatch.group(1);
+      }
+    }
     return "";
   }
 }

querysync/javatests/com/google/idea/blaze/qsync/BUILD

@@ -151,3 +151,15 @@ java_test(
         "@truth//jar",
     ],
 )
+
+java_test(
+    name = "PackageStatementParserTest",
+    size = "small",
+    srcs = ["PackageStatementParserTest.java"],
+    deps = [
+        "//querysync/java/com/google/idea/blaze/qsync",
+        "@com_google_guava_guava//jar",
+        "@junit//jar",
+        "@truth//jar",
+    ],
+)

querysync/javatests/com/google/idea/blaze/qsync/PackageStatementParserTest.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2023 The Bazel Authors. All rights reserved.
+ *
+ * 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 com.google.idea.blaze.qsync;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.base.Joiner;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class PackageStatementParserTest {
+
+  @Test
+  public void basic_package_statement() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    Joiner.on("\n")
+                        .join("package com.myorg.somepackage;", "", "public class MyClass {}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.somepackage");
+  }
+
+  @Test
+  public void comment_before_package_statement() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    Joiner.on("\n")
+                        .join(
+                            "/**",
+                            " * Copyright statement!",
+                            " * Another line",
+                            " */",
+                            "package com.myorg.otherpackage;",
+                            "",
+                            "public class MyClass {}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.otherpackage");
+  }
+
+  @Test
+  public void single_line_generated_file() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    ("/* This is a generated file */package com.myorg.package.generated;public"
+                         + " final class SomeClass {public final static boolean GENERATED_THING ="
+                         + " true;}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.package.generated");
+  }
+
+  @Test
+  public void basic_kotlin() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    Joiner.on("\n")
+                        .join(
+                            "package com.myorg.kotlinpackage",
+                            "",
+                            "import kotlin.text.*",
+                            "",
+                            "fun main() {",
+                            "    println(\"Hello world!\")",
+                            "}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.kotlinpackage");
+  }
+
+  @Test
+  public void kotlin_package_annotation() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    Joiner.on("\n")
+                        .join(
+                            "@file:JvmName(\"MyFile\")",
+                            "package com.myorg.kotlinpackage",
+                            "",
+                            "object MyObject {",
+                            "}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.kotlinpackage");
+  }
+
+  @Test
+  public void kotlin_shebang() throws IOException {
+    PackageStatementParser psp = new PackageStatementParser();
+    assertThat(
+            psp.readPackage(
+                new ByteArrayInputStream(
+                    Joiner.on("\n")
+                        .join(
+                            "#!/bin/interpreter",
+                            "package com.myorg.kotlinpackage",
+                            "",
+                            "object MyObject {",
+                            "}")
+                        .getBytes(StandardCharsets.UTF_8))))
+        .isEqualTo("com.myorg.kotlinpackage");
+  }
+}