IDEA-209947 Report obviously not-null values; better propagation through assignment

GitOrigin-RevId: 2f6cd06b9750e8f080ab543af40b522f4c2bfefa

java/java-tests/testData/inspection/dataFlow/tracker/IndexOfPlusOne.java

@@ -0,0 +1,19 @@
+/*
+Value is always true (j >= 0)
+  Left operand is >= 0 (j)
+    'j' was assigned (i + 1)
+      Result of '+' is >= 0 (i + 1)
+        Left operand is in {-1..Integer.MAX_VALUE-1} (i)
+          'i' was assigned (s.indexOf(' '))
+            Value is in {-1..Integer.MAX_VALUE-1} (s.indexOf(' '))
+ */
+
+class Test {
+  private static void dosmth(String s) {
+    int i = s.indexOf(' ');
+    int j = i + 1;
+    if (<selection>j >= 0</selection>) {
+
+    }
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/NotNullAssignmentInside.java

@@ -0,0 +1,12 @@
+/*
+Value is always true ((s = new Object()) != null)
+  's' was assigned (new Object())
+    Expression cannot be null as it's newly created object (new Object())
+ */
+
+class Test {
+  void test() {
+    Object s;
+    if (<selection>(s = new Object()) != null</selection>) {}
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/NotNullObvious.java

@@ -0,0 +1,12 @@
+/*
+Value is always true (s != null)
+  's' was assigned (new Object())
+    Expression cannot be null as it's newly created object (new Object())
+ */
+
+class Test {
+  void test() {
+    Object s = (new Object());
+    if (<selection>s != null</selection>) {}
+  }
+}