Make if-else-false-to-and avoid redundant and (#468)

Author: jackfirth

default-recommendations/conditional-shortcuts-test.rkt

@@ -62,6 +62,11 @@ test: "multi-line if else false can be refactored to a multi-line and expression
 ------------------------------
 
 
+test: "if and else false can be refactored to a single and expression"
+- (if (and 'a 'b) 'c #f)
+- (and 'a 'b 'c)
+
+
 test: "if x else x can be refactored to an and expression"
 ------------------------------
 (define x 'a)
@@ -87,6 +92,17 @@ test: "multi-line if x else x can be refactored to a multi-line and expression"
 ------------------------------
 
 
+test: "if x then and expression else x can be refactored to a single and expression"
+------------------------------
+(define x 'a)
+(if x (and 'b 'c 'd) x)
+------------------------------
+------------------------------
+(define x 'a)
+(and x 'b 'c 'd)
+------------------------------
+
+
 test: "if expressions can be refactored to when expressions when equivalent"
 ------------------------------
 (if #true

default-recommendations/conditional-shortcuts.rkt

@@ -49,17 +49,17 @@
 
 (define-refactoring-rule if-else-false-to-and
   #:description equivalent-conditional-description
-  #:literals (if)
-  (if condition then-branch #false)
-  (and condition then-branch))
+  #:literals (if and)
+  (if (~or (and condition-part:expr ...) condition:expr) then-branch #false)  
+  (and (~? (~@ condition-part ...) condition) then-branch))
 
 
 (define-refactoring-rule if-x-else-x-to-and
   #:description equivalent-conditional-description
-  #:literals (if)
-  (if x:id then-branch:expr y:id)
-  #:when (free-identifier=? #'x #'y)
-  (and x then-branch))
+  #:literals (if and)
+  (if x:id (~or (and then-part ...) then-branch:expr) y:id)
+  #:when (free-identifier=? (attribute x) (attribute y))
+  (and x (~? (~@ then-part ...) then-branch)))
 
 
 (define-syntax-class block-expression