Address comments

ql/src/codeql_ruby/ast/Call.qll

@@ -85,6 +85,21 @@ class MethodCall extends Call, TMethodCall {
    */
   Expr getReceiver() { none() }
 
+  /**
+   * Holds if the receiver is `self` or there is no receiver, which has the same
+   * meaning as an explict `self`. For example:
+   *
+   * ```rb
+   * self.foo
+   * foo
+   * ```
+   */
+  predicate receiverIsSelf() {
+    this.getReceiver() instanceof Self
+    or
+    not exists(this.getReceiver())
+  }
+
   /**
    * Gets the name of the method being called. For example, in:
    *

ql/src/codeql_ruby/ast/Method.qll

@@ -8,13 +8,13 @@ private import internal.TreeSitter
  * A representation of a method.
  */
 class Method extends TMethod {
-  /** Get a declaration of this module, if any. */
+  /** Gets a declaration of this module, if any. */
   MethodBase getADeclaration() { result.getMethod() = this }
 
-  /** Get the name of this method */
+  /** Gets the name of this method */
   string getName() { this = TInstanceMethod(_, result) }
 
-  /** Get the module in which this method is defined */
+  /** Gets the module in which this method is defined */
   Module getModule() { this = TInstanceMethod(result, _) }
 
   /** Gets a textual representation of this method. */

ql/src/codeql_ruby/ast/Module.qll

@@ -8,22 +8,22 @@ private import internal.TreeSitter
  * A representation of a run-time `module` or `class` value.
  */
 class Module extends TModule {
-  /** Get a declaration of this module, if any. */
+  /** Gets a declaration of this module, if any. */
   ModuleBase getADeclaration() { result.getModule() = this }
 
-  /** Get the super class of this module, if any. */
+  /** Gets the super class of this module, if any. */
   Module getSuperClass() { result = getSuperClass(this) }
 
-  /** Get a method defined in this module by name. */
+  /** Gets a method defined in this module by name. */
   Method getMethod(string name) { result.getName() = name and result.getModule() = this }
 
   /** Look up a method in this module's ancestor chain. */
   Method lookupMethod(string name) { result = lookupMethod(this, name) }
 
-  /** Get a `prepend`ed module. */
+  /** Gets a `prepend`ed module. */
   Module getAPrependedModule() { result = getAPrependedModule(this) }
 
-  /** Get an `include`d module. */
+  /** Gets an `include`d module. */
   Module getAnIncludedModule() { result = getAnIncludedModule(this) }
 
   /** Gets a textual representation of this module. */

ql/src/codeql_ruby/ast/internal/Module.qll

@@ -67,11 +67,7 @@ private module Cached {
         m = resolveScopeExpr(c.getReceiver())
         or
         m = enclosingModule(c).getModule() and
-        (
-          c.getReceiver() instanceof Self
-          or
-          not exists(c.getReceiver())
-        )
+        c.receiverIsSelf()
       ) and
       result = resolveScopeExpr(c.getAnArgument())
     )
@@ -85,11 +81,7 @@ private module Cached {
         m = resolveScopeExpr(c.getReceiver())
         or
         m = enclosingModule(c).getModule() and
-        (
-          c.getReceiver() instanceof Self
-          or
-          not exists(c.getReceiver())
-        )
+        c.receiverIsSelf()
       ) and
       result = resolveScopeExpr(c.getAnArgument())
     )