chore: add ErrorProne (#258)

* BROKE: Switch on ErrorProne, and Nullaway, and get to compile-clean (tests still br0ked)

* FAIL: WIP - testCompile passes, but some tests fail

* Build green

* Ready for merge?

api/pom.xml

@@ -43,6 +43,11 @@
       <artifactId>wildfly-elytron-x500-cert</artifactId>
     </dependency>
 
+    <dependency>
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+    </dependency>
+
     <!-- Test dependencies -->
 
     <dependency>

api/src/main/java/com/redhat/insights/Filtering.java

@@ -5,8 +5,10 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Function;
+import org.jspecify.annotations.NullMarked;
 
 /** Insights data filtering function. */
+@NullMarked
 public enum Filtering implements Function<Map<String, Object>, Map<String, Object>> {
   DEFAULT(Utils::defaultMasking),
 
@@ -20,6 +22,7 @@ public enum Filtering implements Function<Map<String, Object>, Map<String, Objec
     this.mask = mask;
   }
 
+  @Override
   public Map<String, Object> apply(Map<String, Object> unfiltered) {
     return mask.apply(unfiltered);
   }

api/src/main/java/com/redhat/insights/InsightsCustomScheduledExecutor.java

@@ -8,8 +8,10 @@
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import org.jspecify.annotations.NullMarked;
 
 /** A scheduler based on a single-threaded {@link ScheduledThreadPoolExecutor}. */
+@NullMarked
 public class InsightsCustomScheduledExecutor extends ScheduledThreadPoolExecutor
     implements InsightsScheduler {
   private final InsightsLogger logger;

api/src/main/java/com/redhat/insights/InsightsErrorCode.java

@@ -1,11 +1,14 @@
-/* Copyright (C) Red Hat 2022-2023 */
+/* Copyright (C) Red Hat 2022-2024 */
 package com.redhat.insights;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * Client internal errors.
  *
  * @author Emmanuel Hugonnet (c) 2023 Red Hat, Inc.
  */
+@NullMarked
 public enum InsightsErrorCode {
   NONE(0),
   OPT_OUT(1),

api/src/main/java/com/redhat/insights/InsightsException.java

@@ -1,14 +1,17 @@
-/* Copyright (C) Red Hat 2023 */
+/* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights;
 
 import static com.redhat.insights.InsightsErrorCode.NONE;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * General-purpose insights client exception type.
  *
  * <p>Lower-level exceptions (IO, etc.) shall be wrapped or attached to an {@link
  * InsightsException}.
  */
+@NullMarked
 public final class InsightsException extends RuntimeException {
 
   private final InsightsErrorCode error;
@@ -42,6 +45,6 @@ public InsightsException(InsightsErrorCode error, Throwable cause) {
 
   @Override
   public String getMessage() {
-    return error.formatMessage(super.getMessage());
+    return error.formatMessage(String.valueOf(super.getMessage()));
   }
 }

api/src/main/java/com/redhat/insights/InsightsReportController.java

@@ -16,6 +16,7 @@
 import java.security.NoSuchAlgorithmException;
 import java.util.concurrent.*;
 import java.util.function.Supplier;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * The controller class has primarily responsibility for managing the upload of {@code CONNECT} and
@@ -24,6 +25,7 @@
  * <p>Client code must explicitly manage the lifecycle of the controller object, and shut it down at
  * application exit.
  */
+@NullMarked
 public final class InsightsReportController {
 
   private final InsightsLogger logger;

api/src/main/java/com/redhat/insights/InsightsScheduler.java

@@ -1,10 +1,12 @@
-/* Copyright (C) Red Hat 2023 */
+/* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights;
 
 import java.util.List;
 import java.util.concurrent.ScheduledFuture;
+import org.jspecify.annotations.NullMarked;
 
 /** Interface for scheduling {@code CONNECT} and {@code UPDATE} events. */
+@NullMarked
 public interface InsightsScheduler {
 
   /**

api/src/main/java/com/redhat/insights/config/DefaultInsightsConfiguration.java

@@ -1,8 +1,11 @@
-/* Copyright (C) Red Hat 2023 */
+/* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights.config;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * Base configuration that uses the default methods from {@link InsightsConfiguration}, and where
  * only {@link InsightsConfiguration#getIdentificationName()} needs to be overridden.
  */
+@NullMarked
 public abstract class DefaultInsightsConfiguration implements InsightsConfiguration {}

api/src/main/java/com/redhat/insights/config/EnvAndSysPropsInsightsConfiguration.java

@@ -6,13 +6,15 @@
 import com.redhat.insights.InsightsException;
 import java.time.Duration;
 import java.util.Optional;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * Configuration where values from {@link DefaultInsightsConfiguration} can be overridden by
  * environment variables and system properties.
  *
  * <p>Environment variables take priority over system properties.
  */
+@NullMarked
 public class EnvAndSysPropsInsightsConfiguration extends DefaultInsightsConfiguration {
 
   public static final String ENV_IDENTIFICATION_NAME = "RHT_INSIGHTS_JAVA_IDENTIFICATION_NAME";

api/src/main/java/com/redhat/insights/config/InsightsConfiguration.java

@@ -3,11 +3,13 @@
 
 import java.time.Duration;
 import java.util.Optional;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * Insights client configuration, covering topics such as PEM file locations, endpoint parameters,
  * proxing and more.
  */
+@NullMarked
 public interface InsightsConfiguration {
 
   String DEFAULT_RHEL_CERT_FILE_PATH = "/etc/pki/consumer/cert.pem";

api/src/main/java/com/redhat/insights/http/BackoffWrapper.java

@@ -7,13 +7,15 @@
 import com.redhat.insights.InsightsException;
 import com.redhat.insights.config.InsightsConfiguration;
 import com.redhat.insights.logging.InsightsLogger;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * A general-purpose exponential backoff implementation.
  *
  * <p>It wraps an execution that might throw an exception (see {@link Action}). In this case
  * attempts will be retried with the provided parameters (count, initial delay, factor).
  */
+@NullMarked
 public final class BackoffWrapper {
 
   @FunctionalInterface

api/src/main/java/com/redhat/insights/http/InsightsFileWritingClient.java

@@ -14,7 +14,10 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
+import org.jspecify.annotations.NullMarked;
 
+/** A client that writes the insights report to a file. */
+@NullMarked
 public class InsightsFileWritingClient implements InsightsHttpClient {
   private final InsightsLogger logger;
   private final InsightsConfiguration config;

api/src/main/java/com/redhat/insights/http/InsightsHttpClient.java

@@ -1,4 +1,4 @@
-/* Copyright (C) Red Hat 2023 */
+/* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights.http;
 
 import static com.redhat.insights.InsightsErrorCode.ERROR_GZIP_FILE;
@@ -8,14 +8,17 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
 import java.util.zip.GZIPOutputStream;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * The main interface used for delivering Insights data (aka archives) to Red Hat. Note that the
  * interface name contains "Http" because the primary (and desired) transport is over HTTPS.
  * However, we need to also support a file-based mechanism - but only temporarily - so we don't warp
  * the interface name.
  */
+@NullMarked
 public interface InsightsHttpClient {
 
   public static final String GENERAL_MIME_TYPE =
@@ -72,7 +75,8 @@ static byte[] gzipReport(final byte[] report) {
       gzip.close();
       return baos.toByteArray();
     } catch (IOException iox) {
-      throw new InsightsException(ERROR_GZIP_FILE, "Failed to GZIP report: " + report, iox);
+      throw new InsightsException(
+          ERROR_GZIP_FILE, "Failed to GZIP report: " + Arrays.toString(report), iox);
     }
   }
 }

api/src/main/java/com/redhat/insights/http/InsightsMultiClient.java

@@ -1,4 +1,4 @@
-/* Copyright (C) Red Hat 2023 */
+/* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights.http;
 
 import static com.redhat.insights.InsightsErrorCode.ERROR_CLIENT_FAILED;
@@ -8,11 +8,13 @@
 import com.redhat.insights.reports.InsightsReport;
 import java.util.Arrays;
 import java.util.List;
+import org.jspecify.annotations.NullMarked;
 
 /**
  * An implementation of the Insights client interface that can try multiple connection paths. This
  * includes the expected primary use case of HTTPS, then File.
  */
+@NullMarked
 public class InsightsMultiClient implements InsightsHttpClient {
   private final InsightsLogger logger;
   private final List<InsightsHttpClient> clients;

api/src/main/java/com/redhat/insights/jars/JarAnalyzer.java

@@ -138,21 +138,20 @@ private JarInfo getJarInfo(String jarFilename, URL url, Map<String, String> attr
       try {
         getExtraAttributes(jarInputStream, attributes);
 
-        Map<String, String> pom = getPom(jarInputStream);
+        Optional<Map<String, String>> oPom = getPom(jarInputStream);
 
         // if we find exactly one pom, use it
-        if (pom != null) {
+        if (oPom.isPresent()) {
+          Map<String, String> pom = oPom.get();
           attributes.putAll(pom);
-          return new JarInfo(jarFilename, pom.get("version"), attributes);
+          return new JarInfo(jarFilename, pom.getOrDefault("version", UNKNOWN_VERSION), attributes);
         }
       } catch (Exception ex) {
         logger.error(url + "Exception getting extra attributes or pom", ex);
       }
 
-      String version = getVersion(jarInputStream);
-      if (version == null || "".equals(version)) {
-        version = UNKNOWN_VERSION;
-      }
+      Optional<String> oVersion = getVersion(jarInputStream);
+      String version = oVersion.orElse(UNKNOWN_VERSION);
 
       return new JarInfo(jarFilename, version, attributes);
     }
@@ -163,26 +162,26 @@ private JarInfo getJarInfo(String jarFilename, URL url, Map<String, String> attr
    * are found, return null.
    */
   @SuppressWarnings({"unchecked", "rawtypes"})
-  private static Map<String, String> getPom(JarInputStream jarFile) throws IOException {
-    Map<String, String> pom = null;
+  private static Optional<Map<String, String>> getPom(JarInputStream jarFile) throws IOException {
+    Optional<Map<String, String>> out = Optional.empty();
 
     for (JarEntry entry = jarFile.getNextJarEntry();
         entry != null;
         entry = jarFile.getNextJarEntry()) {
       if (entry.getName().startsWith("META-INF/maven")
           && entry.getName().endsWith("pom.properties")) {
-        if (pom != null) {
+        if (out.isPresent()) {
           // we've found multiple pom files. bail!
-          return null;
+          return Optional.empty();
         }
         Properties props = new Properties();
         props.load(jarFile);
 
-        pom = (Map) props;
+        out = Optional.of((Map) props);
       }
     }
 
-    return pom;
+    return out;
   }
 
   static void getExtraAttributes(JarInputStream jarFile, Map<String, String> map) {
@@ -200,13 +199,13 @@ static void getExtraAttributes(JarInputStream jarFile, Map<String, String> map)
     }
   }
 
-  static String getVersion(JarInputStream jarFile) {
+  static Optional<String> getVersion(JarInputStream jarFile) {
     Manifest manifest = jarFile.getManifest();
     if (manifest == null) {
-      return null;
+      return Optional.empty();
     }
 
-    return JarUtils.getVersionFromManifest(manifest);
+    return Optional.of(JarUtils.getVersionFromManifest(manifest));
   }
 
   /**

api/src/main/java/com/redhat/insights/reports/AbstractTopLevelReportBase.java

@@ -14,6 +14,7 @@
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Base class that collects basic information and delegates to the subreport for product-specific
@@ -84,7 +85,7 @@ public abstract class AbstractTopLevelReportBase implements InsightsReport {
   private final JsonSerializer<InsightsReport> serializer;
   private final InsightsLogger logger;
   private final InsightsConfiguration config;
-  private byte[] subReport;
+  private byte @Nullable [] subReport;
 
   // Can't be set properly until after report has been generated
   private String idHash = "";

api/src/main/java/com/redhat/insights/reports/Utils.java

@@ -1,6 +1,8 @@
 /* Copyright (C) Red Hat 2023-2024 */
 package com.redhat.insights.reports;
 
+import static java.util.Collections.emptyMap;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -11,11 +13,13 @@ private Utils() {}
   @SuppressWarnings("unchecked")
   public static Map<String, Object> defaultMasking(final Map<String, Object> inArgs) {
     List<String> jvmArgs = new ArrayList<>();
-    for (String arg : (List<String>) (inArgs.get("jvm.args"))) {
+    List<String> args = (List<String>) (inArgs.getOrDefault("jvm.args", emptyMap()));
+    for (String arg : args) {
       jvmArgs.add(sanitizeJavaParameters(arg));
     }
     inArgs.put("jvm.args", jvmArgs);
-    inArgs.put("java.command", sanitizeJavaParameters((String) inArgs.get("java.command")));
+    String command = (String) inArgs.getOrDefault("java.command", "");
+    inArgs.put("java.command", sanitizeJavaParameters(command));
     return inArgs;
   }