Implemented first version of JoinAssertThatStatements inspection that will try to merge assertThat() statements with the same actual object together, preserving comments.

src/test/resources/inspections/JoinStatements/JoinStatementsAfter.java

@@ -0,0 +1,40 @@
+import java.util.*;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JoinStatements {
+
+    private void joinStatements() {
+        List<String> list = new ArrayList<>();
+        // the future is always born in pain
+        /* tricky */
+        assertThat(list).as("foo").hasSize(2)
+                /* do another */
+                /* do one */.as("bar").contains("barbar")
+                // comment to keep
+                .doesNotContain("barbara") // another comment to keep
+                .doesNotContain("wrzlbrmpft")
+                /* and a multi line comment
+                    after the statement */
+                // across two lines
+                .as("etc")/* what a nasty comment */.contains("etcetc")
+                // moar!
+                .doesNotContain("foobar");
+
+        assertThat("narf").isNotEqualTo("puit").as("bar").contains("barbar").as("foo").hasSize(2);
+        assertThat(list).as("evil").extracting(String::length).contains(2);
+
+        assertThat(list).as("bar").contains("barbar");
+        assertThat("narf").isNotEqualTo("puit").as("foo").hasSize(2);
+        if (true) {
+            assertThat(list).doesNotContain("narf").as("bar").contains("barbar");
+        }
+        assertThat(list.get(0)).isNotEmpty().hasSize(3).isEqualTo("bar");
+
+        assertThat(list.get(0) + "foo").isEqualTo("bar").doesNotStartWith("foo");
+
+        Iterator<String> iterator = list.iterator();
+        assertThat(iterator.next()).isEqualTo("foo");
+        assertThat(iterator.next()).isEqualTo("bar");
+    }
+}

src/test/resources/inspections/JoinStatements/JoinStatementsBefore.java

@@ -0,0 +1,44 @@
+import java.util.*;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JoinStatements {
+
+    private void joinStatements() {
+        List<String> list = new ArrayList<>();
+        // the future is always born in pain
+        /* tricky */assertThat(list).as("foo").hasSize(2); /* do one */ /* do another */
+        assertThat(list).as("bar").contains("barbar"); // comment to keep
+        assertThat(list).doesNotContain("barbara") // another comment to keep
+                .doesNotContain("wrzlbrmpft") // across two lines
+        ; /* and a multi line comment
+        after the statement */
+        assertThat(list).as("etc")/* what a nasty comment */.contains("etcetc");
+
+        // moar!
+        assertThat(list).doesNotContain("foobar");
+
+        assertThat("narf").isNotEqualTo("puit");
+        assertThat(list).as("bar").contains("barbar");
+        assertThat(list).as("foo").hasSize(2);
+        assertThat(list).as("evil").extracting(String::length).contains(2);
+
+        assertThat(list).as("bar").contains("barbar");
+        assertThat("narf").isNotEqualTo("puit");
+        assertThat(list).as("foo").hasSize(2);
+        if (true) {
+            assertThat(list).doesNotContain("narf");
+            assertThat(list).as("bar").contains("barbar");
+        }
+        assertThat(list.get(0)).isNotEmpty();
+        assertThat(list.get(0)).hasSize(3);
+        assertThat(list.get(0)).isEqualTo("bar");
+
+        assertThat(list.get(0) + "foo").isEqualTo("bar");
+        assertThat(list.get(0) + "foo").doesNotStartWith("foo");
+
+        Iterator<String> iterator = list.iterator();
+        assertThat(iterator.next()).isEqualTo("foo");
+        assertThat(iterator.next()).isEqualTo("bar");
+    }
+}