Cleanup from code review feedback

Author: JLLeitschuh

java/ql/lib/change-notes/2022-03-07-char-literal-in-compile-time-constant.md

@@ -1,5 +1,5 @@
 ---
 category: minorAnalysis
 ---
- * Add new method `CompileTimeConstantExpr.getStringifiedValue` which attempts to compute the
+ * Add new predicate `CompileTimeConstantExpr.getStringifiedValue` which attempts to compute the
    `String.valueOf` string rendering of a constant expression.

java/ql/lib/semmle/code/java/Expr.qll

@@ -166,10 +166,10 @@ class CompileTimeConstantExpr extends Expr {
    *
    * The stringified version of a compile-time constant expression is the equivalent to
    * the result of calling `String.valueOf(expr)` on the expression.
-   * 
+   *
    * Note that this does not handle the following cases:
    *
-   * - mathematical computations of type `long`.
+   * - mathematical computations of type `long`, `float`, or `double`.
    */
   pragma[nomagic]
   string getStringifiedValue() {
@@ -200,11 +200,11 @@ class CompileTimeConstantExpr extends Expr {
   string getStringValue() {
     result = this.(StringLiteral).getValue()
     or
-    (
-      this.getType() instanceof TypeString and
+    this.getType() instanceof TypeString and // When the expression type is `String`
+    result =
+      // Then the resultant string is the addition of both operands stringified value, regardless of type.
       this.(AddExpr).getLeftOperand().(CompileTimeConstantExpr).getStringifiedValue() +
         this.(AddExpr).getRightOperand().(CompileTimeConstantExpr).getStringifiedValue()
-    )
     or
     // Ternary conditional, with compile-time constant condition.
     exists(ConditionalExpr ce, boolean condition |

java/ql/test/library-tests/constants/CompileTimeConstantExpr.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Expr
+import java
 
 from CompileTimeConstantExpr constant, RefType tpe
 where

java/ql/test/library-tests/constants/getBooleanValue.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Variable
+import java
 
 from Variable v, CompileTimeConstantExpr init, RefType enclosing, boolean constant
 where

java/ql/test/library-tests/constants/getInitializer.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Variable
+import java
 
 from Variable v, Expr init, RefType enclosing
 where

java/ql/test/library-tests/constants/getIntValue.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Variable
+import java
 
 from Variable v, CompileTimeConstantExpr init, RefType enclosing, int constant
 where

java/ql/test/library-tests/constants/getStringValue.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Variable
+import java
 
 from Variable v, CompileTimeConstantExpr init, RefType enclosing, string constant
 where

java/ql/test/library-tests/constants/getStringified.ql

@@ -1,4 +1,4 @@
-import semmle.code.java.Variable
+import java
 
 from Variable v, CompileTimeConstantExpr init, RefType enclosing, string constant
 where