Disable MissingJavadoc on constructors

PiperOrigin-RevId: 940668225

Author: cushon

core/src/main/java/com/google/errorprone/bugpatterns/javadoc/MissingJavadoc.java

@@ -72,6 +72,11 @@ public Description matchMethod(MethodTree methodTree, VisitorState state) {
     if (symbol == null) {
       return NO_MATCH;
     }
+    if (symbol.isConstructor()) {
+      // Constructors have a better than average change of being "self-explanatory":
+      // https://google.github.io/styleguide/javaguide.html#s7.3.1-javadoc-exception-self-explanatory
+      return NO_MATCH;
+    }
     if (!findSuperMethods(symbol, state.getTypes()).isEmpty()) {
       return NO_MATCH;
     }

core/src/test/java/com/google/errorprone/bugpatterns/javadoc/MissingJavadocTest.java

@@ -171,4 +171,18 @@ private static final class Builder {}
             """)
         .doTest();
   }
+
+  @Test
+  public void publicConstructorWithoutJavadoc_passes() {
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            """
+            /** This is class doc. */
+            public class Test {
+              public Test() {}
+            }
+            """)
+        .doTest();
+  }
 }