Add printf-without-specifiers refactoring rule (#709)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: jackfirth <[email protected]>
Co-authored-by: Jacqueline Firth <[email protected]>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: 3 people

default-recommendations/console-io-suggestions-test.rkt

@@ -26,3 +26,18 @@ test: "should suggest 'any linemode with read-line when linemode and port not sp
 (define (foo)
   (read-line (current-input-port) 'any))
 ----------------------------------------
+
+
+test: "printf to display"
+- (printf "foo")
+- (display "foo")
+
+
+test: "printf to displayln"
+- (printf "foo\nbar\n")
+- (displayln "foo\nbar")
+
+
+test: "printf to newline"
+- (printf "\n")
+- (newline)

default-recommendations/console-io-suggestions.rkt

@@ -11,6 +11,7 @@
 
 (require racket/file
          racket/list
+         racket/string
          rebellion/private/static-name
          resyntax/base
          syntax/parse)
@@ -28,5 +29,29 @@
   (read-line (~? port (current-input-port)) 'any))
 
 
+(define-syntax-class printf-without-specifiers
+  #:attributes (refactored)
+  #:literals (printf)
+  
+  (pattern (printf "\n")
+    #:with refactored #'(newline))
+  
+  (pattern (printf s:str)
+    #:when (string-suffix? (syntax-e #'s) "\n")
+    #:with stripped (substring (syntax-e #'s) 0 (- (string-length (syntax-e #'s)) 1))
+    #:with refactored #'(displayln stripped))
+  
+  (pattern (printf s:str)
+    #:with refactored #'(display s)))
+
+
+(define-refactoring-rule printf-to-display
+  #:description
+  "This use of `printf` has no arguments other than the template string."
+  expr:printf-without-specifiers
+  expr.refactored)
+
+
 (define-refactoring-suite console-io-suggestions
-  #:rules (read-line-any))
+  #:rules (printf-to-display
+           read-line-any))