fix:[core] Wrong deprecation warnings for unused XPath attributes

* Improve integration tests in pmd-dist to detect
  warnings about deprecated attributes.
* Wrap the attribute value in a singleton list, to be able to distinguish
  between no value (null in the list) and value not determined yet
  (list is null).
* Add integration test for apex.
* Updated release notes

fixes #2020

docs/pages/release_notes.md

@@ -32,6 +32,7 @@ This is a {{ site.pmd.release_type }} release.
 
 *   core
     *   [#2014](https://github.com/pmd/pmd/issues/2014): \[core] Making add(SourceCode sourceCode) public for alternative file systems
+    *   [#2020](https://github.com/pmd/pmd/issues/2020): \[core] Wrong deprecation warnings for unused XPath attributes
     *   [#2036](https://github.com/pmd/pmd/issues/2036): \[core] Wrong include/exclude patterns are silently ignored
 *   java
     *   [#2042](https://github.com/pmd/pmd/issues/2042): \[java] PMD crashes with ClassFormatError: Absent Code attribute...

pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/Attribute.java

@@ -6,6 +6,8 @@ package net.sourceforge.pmd.lang.ast.xpath;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
@@ -36,7 +38,7 @@ public class Attribute {
     private final Node parent;
     private final String name;
     private Method method;
-    private Object value;
+    private List<?> value;
     private String stringValue;
 
     /** Creates a new attribute belonging to the given node using its accessor. */
@@ -50,7 +52,7 @@ public class Attribute {
     public Attribute(Node parent, String name, String value) {
         this.parent = parent;
         this.name = name;
-        this.value = value;
+        this.value = Collections.singletonList(value);
         this.stringValue = value;
     }
 
@@ -71,20 +73,20 @@ public class Attribute {
     }
 
     public Object getValue() {
-        if (value != null) { // TODO if the method returned null we'll call it again...
+        if (value != null) {
-            return value;
+            return value.get(0);
         }
 
         if (method.isAnnotationPresent(Deprecated.class) && LOG.isLoggable(Level.WARNING)
                 && DETECTED_DEPRECATED_ATTRIBUTES.putIfAbsent(getLoggableAttributeName(), Boolean.TRUE) == null) {
-            // this message needs to be kept in sync with PMDCoverageTest
+            // this message needs to be kept in sync with PMDCoverageTest / BinaryDistributionIT
             LOG.warning("Use of deprecated attribute '" + getLoggableAttributeName() + "' in XPath query");
         }
 
         // this lazy loading reduces calls to Method.invoke() by about 90%
         try {
-            value = method.invoke(parent, EMPTY_OBJ_ARRAY);
+            value = Collections.singletonList(method.invoke(parent, EMPTY_OBJ_ARRAY));
-            return value;
+            return value.get(0);
         } catch (IllegalAccessException | InvocationTargetException iae) {
             iae.printStackTrace();
         }
@@ -95,10 +97,8 @@ public class Attribute {
         if (stringValue != null) {
             return stringValue;
         }
-        Object v = this.value;
+        Object v = getValue();
-        if (this.value == null) {
+
-            v = getValue();
-        }
         stringValue = v == null ? "" : String.valueOf(v);
         return stringValue;
     }

pmd-dist/src/test/java/net/sourceforge/pmd/it/BinaryDistributionIT.java

@@ -90,7 +90,7 @@ public class BinaryDistributionIT {
 
     @Test
     public void runPMD() throws Exception {
-        String srcDir = new File(".", "src/test/resources/sample-source/").getAbsolutePath();
+        String srcDir = new File(".", "src/test/resources/sample-source/java/").getAbsolutePath();
 
         ExecutionResult result;
 
@@ -98,12 +98,38 @@ public class BinaryDistributionIT {
         result.assertExecutionResult(0, "apex, ecmascript, java, jsp, plsql, pom, scala, vf, vm, wsdl, xml, xsl");
 
         result = PMDExecutor.runPMDRules(tempDir, srcDir, "src/test/resources/rulesets/sample-ruleset.xml");
-        result.assertExecutionResult(4, "JumbledIncrementer.java:8:");
+        result.assertExecutionResult(4, "", "JumbledIncrementer.java:8:");
 
         result = PMDExecutor.runPMDRules(tempDir, srcDir, "rulesets/java/quickstart.xml");
         result.assertExecutionResult(4, "");
     }
 
+    @Test
+    public void testAllJavaRules() throws Exception {
+        String srcDir = new File(".", "src/test/resources/sample-source/java/").getAbsolutePath();
+
+        ExecutionResult result = PMDExecutor.runPMDRules(tempDir, srcDir, "src/test/resources/rulesets/all-java.xml");
+        assertDefaultExecutionResult(result);
+    }
+
+    @Test
+    public void testAllApexRules() throws Exception {
+        String srcDir = new File(".", "src/test/resources/sample-source/apex/").getAbsolutePath();
+
+        ExecutionResult result = PMDExecutor.runPMDRules(tempDir, srcDir, "src/test/resources/rulesets/all-apex.xml");
+        assertDefaultExecutionResult(result);
+    }
+
+    private static void assertDefaultExecutionResult(ExecutionResult result) {
+        result.assertExecutionResult(4, "");
+
+        result.assertNoError("Exception applying rule");
+        result.assertNoError("Ruleset not found");
+        result.assertNoError("Use of deprecated attribute");
+        result.assertNoErrorInReport("Error while processing");
+        result.assertNoErrorInReport("Error while parsing");
+    }
+
     @Test
     public void runCPD() throws Exception {
         String srcDir = new File(".", "src/test/resources/sample-source-cpd/").getAbsolutePath();

pmd-dist/src/test/java/net/sourceforge/pmd/it/CpdExecutor.java

@@ -34,7 +34,7 @@ public class CpdExecutor {
         String output = IOUtils.toString(process.getInputStream(), StandardCharsets.UTF_8);
 
         int result = process.waitFor();
-        return new ExecutionResult(result, output);
+        return new ExecutionResult(result, output, null, null);
     }
 
     private static ExecutionResult runCpdWindows(Path tempDir, String ... arguments) throws Exception {
@@ -46,7 +46,7 @@ public class CpdExecutor {
         String output = IOUtils.toString(process.getInputStream(), StandardCharsets.UTF_8);
 
         int result = process.waitFor();
-        return new ExecutionResult(result, output);
+        return new ExecutionResult(result, output, null, null);
     }
 
     /**

pmd-dist/src/test/java/net/sourceforge/pmd/it/ExecutionResult.java

@@ -5,7 +5,9 @@
 package net.sourceforge.pmd.it;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import net.sourceforge.pmd.PMD;
@@ -18,10 +20,14 @@ import net.sourceforge.pmd.PMD;
 public class ExecutionResult {
     private final int exitCode;
     private final String output;
+    private final String errorOutput;
+    private final String report;
 
-    ExecutionResult(int theExitCode, String theOutput) {
+    ExecutionResult(int theExitCode, String theOutput, String theErrorOutput, String theReport) {
         this.exitCode = theExitCode;
         this.output = theOutput;
+        this.errorOutput = theErrorOutput;
+        this.report = theReport;
     }
 
     @Override
@@ -30,7 +36,9 @@ public class ExecutionResult {
         sb.append("ExecutionResult:")
             .append(PMD.EOL)
             .append(" exit code: ").append(exitCode).append(PMD.EOL)
-            .append(" output:").append(PMD.EOL).append(output).append(PMD.EOL);
+            .append(" output:").append(PMD.EOL).append(output).append(PMD.EOL)
+            .append(" errorOutput:").append(PMD.EOL).append(errorOutput).append(PMD.EOL)
+            .append(" report:").append(PMD.EOL).append(report).append(PMD.EOL);
         return sb.toString();
     }
 
@@ -42,10 +50,80 @@ public class ExecutionResult {
      * @param expectedOutput the output to search for
      */
     public void assertExecutionResult(int expectedExitCode, String expectedOutput) {
-        assertEquals("Command exited with wrong code", expectedExitCode, exitCode);
+        assertExecutionResult(expectedExitCode, expectedOutput, null);
+    }
+
+    /**
+     * Asserts that the command exited with the expected exit code and that the given expected
+     * output is contained in the actual command output and the given expected report is in the
+     * generated report.
+     *
+     * @param expectedExitCode the exit code, e.g. 0 if no rule violations are expected, or 4 if violations are found
+     * @param expectedOutput the output to search for
+     * @param expectedReport the string to search for tin the report
+     */
+    public void assertExecutionResult(int expectedExitCode, String expectedOutput, String expectedReport) {
+        assertEquals("Command exited with wrong code.\nComplete result:\n\n" + this, expectedExitCode, exitCode);
         assertNotNull("No output found", output);
-        if (!output.contains(expectedOutput)) {
+        if (expectedOutput != null && !expectedOutput.isEmpty()) {
-            fail("Expected output '" + expectedOutput + "' not present.\nComplete output:\n\n" + output);
+            if (!output.contains(expectedOutput)) {
+                fail("Expected output '" + expectedOutput + "' not present.\nComplete result:\n\n" + this);
+            }
+        } else {
+            assertTrue("The output should have been empty.\nComplete result:\n\n" + this, output.isEmpty());
+        }
+        if (expectedReport != null && !expectedReport.isEmpty()) {
+            assertTrue("Expected report '" + expectedReport + "'.\nComplete result:\n\n" + this,
+                    report.contains(expectedReport));
+        }
+    }
+
+    /**
+     * Asserts that the given error message is not in the error output.
+     * @param errorMessage the error message to search for
+     */
+    public void assertNoError(String errorMessage) {
+        assertFalse("Found error message: " + errorMessage + ".\nComplete result:\n\n" + this,
+                errorOutput.contains(errorMessage));
+    }
+
+    /**
+     * Asserts that the given error message is not in the report.
+     * @param errorMessage the error message to search for
+     */
+    public void assertNoErrorInReport(String errorMessage) {
+        assertFalse("Found error message in report: " + errorMessage + ".\nComplete result:\n\n" + this,
+                report.contains(errorMessage));
+    }
+
+    static class Builder {
+        private int exitCode;
+        private String output;
+        private String errorOutput;
+        private String report;
+
+        Builder withExitCode(int exitCode) {
+            this.exitCode = exitCode;
+            return this;
+        }
+
+        Builder withOutput(String output) {
+            this.output = output;
+            return this;
+        }
+
+        Builder withErrorOutput(String errorOutput) {
+            this.errorOutput = errorOutput;
+            return this;
+        }
+
+        Builder withReport(String report) {
+            this.report = report;
+            return this;
+        }
+
+        ExecutionResult build() {
+            return new ExecutionResult(exitCode, output, errorOutput, report);
         }
     }
 }

pmd-dist/src/test/java/net/sourceforge/pmd/it/PMDExecutor.java

@@ -4,9 +4,13 @@
 
 package net.sourceforge.pmd.it;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.SystemUtils;
@@ -24,33 +28,65 @@ public class PMDExecutor {
     private static final String RULESET_FLAG = "-R";
     private static final String FORMAT_FLAG = "-f";
     private static final String FORMATTER = "text";
+    private static final String REPORTFILE_FLAG = "-r";
 
     private PMDExecutor() {
         // this is a helper class only
     }
 
-    private static ExecutionResult runPMDUnix(Path tempDir, String ... arguments) throws Exception {
+    private static ExecutionResult runPMDUnix(Path tempDir, Path reportFile, String ... arguments) throws Exception {
         String cmd = tempDir.resolve(PMD_BIN_PREFIX + PMDVersion.VERSION + "/bin/run.sh").toAbsolutePath().toString();
-        ProcessBuilder pb = new ProcessBuilder(cmd, "pmd");
+        return runPMD(cmd, Arrays.asList(arguments), reportFile);
-        pb.command().addAll(Arrays.asList(arguments));
-        pb.redirectErrorStream(true);
-        Process process = pb.start();
-        String output = IOUtils.toString(process.getInputStream(), StandardCharsets.UTF_8);
-
-        int result = process.waitFor();
-        return new ExecutionResult(result, output);
     }
 
-    private static ExecutionResult runPMDWindows(Path tempDir, String ... arguments) throws Exception {
+    private static ExecutionResult runPMDWindows(Path tempDir, Path reportFile, String ... arguments) throws Exception {
         String cmd = tempDir.resolve(PMD_BIN_PREFIX + PMDVersion.VERSION + "/bin/pmd.bat").toAbsolutePath().toString();
-        ProcessBuilder pb = new ProcessBuilder(cmd);
+        return runPMD(cmd, Arrays.asList(arguments), reportFile);
-        pb.command().addAll(Arrays.asList(arguments));
+    }
-        pb.redirectErrorStream(true);
-        Process process = pb.start();
-        String output = IOUtils.toString(process.getInputStream(), StandardCharsets.UTF_8);
 
-        int result = process.waitFor();
+    private static ExecutionResult runPMD(String cmd, List<String> arguments, Path reportFile) throws Exception {
-        return new ExecutionResult(result, output);
+        ProcessBuilder pb = new ProcessBuilder(cmd, "pmd");
+        pb.command().addAll(arguments);
+        pb.redirectErrorStream(false);
+        final Process process = pb.start();
+        final ExecutionResult.Builder result = new ExecutionResult.Builder();
+
+        Thread outputReader = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                String output;
+                try {
+                    output = IOUtils.toString(process.getInputStream(), StandardCharsets.UTF_8);
+                    result.withOutput(output);
+                } catch (IOException e) {
+                    result.withOutput("Exception occurred: " + e.toString());
+                }
+            }
+        });
+        outputReader.start();
+        Thread errorReader = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                String error;
+                try {
+                    error = IOUtils.toString(process.getErrorStream(), StandardCharsets.UTF_8);
+                    result.withErrorOutput(error);
+                } catch (IOException e) {
+                    result.withErrorOutput("Exception occurred: " + e.toString());
+                }
+            }
+        });
+        errorReader.start();
+
+        int exitCode = process.waitFor();
+        outputReader.join(TimeUnit.MINUTES.toMillis(5));
+        errorReader.join(TimeUnit.MINUTES.toMillis(5));
+
+        String report = null;
+        if (reportFile != null) {
+            report = IOUtils.toString(reportFile.toUri(), StandardCharsets.UTF_8);
+        }
+        return result.withExitCode(exitCode).withReport(report).build();
     }
 
     /**
@@ -63,10 +99,15 @@ public class PMDExecutor {
      * @throws Exception if the execution fails for any reason (executable not found, ...)
      */
     public static ExecutionResult runPMDRules(Path tempDir, String sourceDirectory, String ruleset) throws Exception {
+        Path reportFile = Files.createTempFile("pmd-it-report", "txt");
+        reportFile.toFile().deleteOnExit();
+
         if (SystemUtils.IS_OS_WINDOWS) {
-            return runPMDWindows(tempDir, SOURCE_DIRECTORY_FLAG, sourceDirectory, RULESET_FLAG, ruleset, FORMAT_FLAG, FORMATTER);
+            return runPMDWindows(tempDir, reportFile, SOURCE_DIRECTORY_FLAG, sourceDirectory, RULESET_FLAG, ruleset,
+                    FORMAT_FLAG, FORMATTER, REPORTFILE_FLAG, reportFile.toAbsolutePath().toString());
         } else {
-            return runPMDUnix(tempDir, SOURCE_DIRECTORY_FLAG, sourceDirectory, RULESET_FLAG, ruleset, FORMAT_FLAG, FORMATTER);
+            return runPMDUnix(tempDir, reportFile, SOURCE_DIRECTORY_FLAG, sourceDirectory, RULESET_FLAG, ruleset,
+                    FORMAT_FLAG, FORMATTER, REPORTFILE_FLAG, reportFile.toAbsolutePath().toString());
         }
     }
 
@@ -79,9 +120,9 @@ public class PMDExecutor {
      */
     public static ExecutionResult runPMD(Path tempDir, String ... arguments) throws Exception {
         if (SystemUtils.IS_OS_WINDOWS) {
-            return runPMDWindows(tempDir, arguments);
+            return runPMDWindows(tempDir, null, arguments);
         } else {
-            return runPMDUnix(tempDir, arguments);
+            return runPMDUnix(tempDir, null, arguments);
         }
     }
 }

pmd-dist/src/test/resources/rulesets/all-apex.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+
+<ruleset name="All Apex Rules" 
+    xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+    <description>Every Apex Rule in PMD</description>
+
+    <rule ref="category/apex/bestpractices.xml" />
+    <rule ref="category/apex/codestyle.xml" />
+    <rule ref="category/apex/design.xml" />
+    <rule ref="category/apex/documentation.xml" />
+    <rule ref="category/apex/errorprone.xml" />
+    <rule ref="category/apex/multithreading.xml" />
+    <rule ref="category/apex/performance.xml" />
+    <rule ref="category/apex/security.xml" />
+
+</ruleset>

pmd-dist/src/test/resources/rulesets/all-java.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+
+<ruleset name="All Java Rules" 
+    xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+    <description>Every Java Rule in PMD</description>
+
+    <rule ref="category/java/bestpractices.xml" />
+    <rule ref="category/java/codestyle.xml" />
+    <rule ref="category/java/design.xml" />
+    <rule ref="category/java/documentation.xml" />
+    <rule ref="category/java/errorprone.xml" />
+    <rule ref="category/java/multithreading.xml" />
+    <rule ref="category/java/performance.xml" />
+    <rule ref="category/java/security.xml" />
+
+</ruleset>