PRP-10968 Flag discouraged time zone-dependent APIs (#9)

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/TimeZoneUsageCheck.java

@@ -0,0 +1,62 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.instanceMethod;
+import static com.google.errorprone.matchers.Matchers.staticMethod;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.BugPattern.LinkType;
+import com.google.errorprone.BugPattern.SeverityLevel;
+import com.google.errorprone.BugPattern.StandardTags;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.MethodInvocationTree;
+import java.time.Clock;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+
+/** A {@link BugChecker} which flags illegal time-zone related operations. */
+@AutoService(BugChecker.class)
+@BugPattern(
+    name = "TimeZoneUsage",
+    summary =
+        "Derive the current time from an existing `Clock` Spring bean, and don't rely on a `Clock`'s time zone",
+    linkType = LinkType.NONE,
+    severity = SeverityLevel.WARNING,
+    tags = StandardTags.FRAGILE_CODE)
+public final class TimeZoneUsageCheck extends BugChecker implements MethodInvocationTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<ExpressionTree> IS_BANNED_TIME_METHOD =
+      anyOf(
+          instanceMethod().onDescendantOf(Clock.class.getName()).namedAnyOf("getZone", "withZone"),
+          staticMethod()
+              .onClass(Clock.class.getName())
+              .namedAnyOf(
+                  "system",
+                  "systemDefaultZone",
+                  "systemUTC",
+                  "tickMillis",
+                  "tickMinutes",
+                  "tickSeconds"),
+          staticMethod()
+              .onClassAny(
+                  Instant.class.getName(),
+                  LocalDate.class.getName(),
+                  LocalDateTime.class.getName(),
+                  LocalTime.class.getName())
+              .named("now"));
+
+  @Override
+  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
+    return IS_BANNED_TIME_METHOD.matches(tree, state)
+        ? buildDescription(tree).build()
+        : Description.NO_MATCH;
+  }
+}

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/TimeZoneUsageCheckTest.java

@@ -0,0 +1,83 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.common.base.Predicates;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+public final class TimeZoneUsageCheckTest {
+  private final CompilationTestHelper compilationHelper =
+      CompilationTestHelper.newInstance(TimeZoneUsageCheck.class, getClass())
+          .expectErrorMessage(
+              "X",
+              Predicates.containsPattern(
+                  "Derive the current time from an existing `Clock` Spring bean, and don't rely on a `Clock`'s time zone"));
+
+  @Test
+  public void testIdentification() {
+    compilationHelper
+        .addSourceLines(
+            "A.java",
+            "import static java.time.ZoneOffset.UTC;",
+            "",
+            "import java.time.Clock;",
+            "import java.time.Duration;",
+            "import java.time.Instant;",
+            "import java.time.LocalDate;",
+            "import java.time.LocalDateTime;",
+            "import java.time.LocalTime;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    Clock clock = Clock.fixed(Instant.EPOCH, UTC);",
+            "    clock.instant();",
+            "    clock.millis();",
+            "    Clock.offset(clock, Duration.ZERO);",
+            "    Clock.tick(clock, Duration.ZERO);",
+            "",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.systemUTC();",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.systemDefaultZone();",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.system(UTC);",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.tickMillis(UTC);",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.tickMinutes(UTC);",
+            "    // BUG: Diagnostic matches: X",
+            "    Clock.tickSeconds(UTC);",
+            "    // BUG: Diagnostic matches: X",
+            "    clock.getZone();",
+            "    // BUG: Diagnostic matches: X",
+            "    clock.withZone(UTC);",
+            "",
+            "    // BUG: Diagnostic matches: X",
+            "    Instant.now();",
+            "    // BUG: Diagnostic matches: X",
+            "    Instant.now(clock);",
+            "",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDate.now();",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDate.now(clock);",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDate.now(UTC);",
+            "",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDateTime.now();",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDateTime.now(clock);",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalDateTime.now(UTC);",
+            "",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalTime.now();",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalTime.now(clock);",
+            "    // BUG: Diagnostic matches: X",
+            "    LocalTime.now(UTC);",
+            "  }",
+            "}")
+        .doTest();
+  }
+}