;; The first three lines of this file were inserted by DrRacket. They record metadata ;; about the language level of this file in a form that our tools can easily process. #reader(lib "htdp-advanced-reader.ss" "lang")((modname Z0-tests) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #t #t none #f () #f))) ; Note: this file is written in *advanced*-student ; (because the test-functions do sequences of I/O, rather than return values). ; Your program should be written in "intermediate student with lambda". (require "Z0.rkt") (require "scanner.rkt") (require rackunit) (require "student-extras.rkt") ; solely for `for-each` ;;;;;;;;;;;;;;;;;;; TEST CASES: Z0 ;;;;;;;;;;;;;;;; ; Some expressions to test in a non-automated way: (check-equal? (parse! (create-scanner "34")) 34) (check-equal? (parse! (create-scanner "-34")) -34) (check-equal? (string->expr "34") 34) (check-equal? (string->expr "<34>") (make-paren 34)) (check-equal? (string->expr "[add 3 4]") (make-binop "add" 3 4)) (check-equal? (string->expr "[add <34> [mul 3 4]]") (make-binop "add" (make-paren 34) (make-binop "mul" 3 4))) (check-equal? (string->expr "zero 3 ? 7 : 9") (make-if-zero 3 7 9)) (check-equal? (string->expr "zero <34> ? [mul 3 4] : 7") (make-if-zero (make-paren 34) (make-binop "mul" 3 4) 7)) (check-equal? (string->expr "zero <34> ? [add <34> [mul 3 4]] : zero 3 ? 7 : 9") (make-if-zero (make-paren 34) (make-binop "add" (make-paren 34) (make-binop "mul" 3 4)) (make-if-zero 3 7 9))) (check-equal? (eval 34) 34) (check-equal? (eval (string->expr "<34>")) 34) (check-equal? (eval (string->expr "[add 3 4]")) 7) (check-equal? (eval (string->expr "[sub 3 4 ]")) -1) (check-equal? (eval (string->expr "[mul 3 4]")) 12) (check-equal? (eval (string->expr "zero 3 ? 4 : 5")) 5) (check-equal? (eval (string->expr "zero 0 ? 4 : 5")) 4) (check-equal? (eval (string->expr "zero [sub 4 2] ? [add 1 2] : [add 3 4] ")) 7) (check-equal? (eval (string->expr "zero 7 ? [add 3 4] : 5 ")) 5) (check-equal? (expr->string (string->expr "34")) "34") (check-equal? (expr->string (string->expr "<34>")) "<34>") (check-equal? (expr->string (string->expr "[add 3 4]")) "[add 3 4]") (check-equal? (expr->string (string->expr "[sub 3 4]")) "[sub 3 4]") (check-equal? (expr->string (string->expr " [ mul 3 4 ] ")) "[mul 3 4]") (check-equal? (expr->string (string->expr "zero 3 ? 4 : 5")) "zero 3 ? 4 : 5") (check-equal? (expr->string (string->expr "zero 0 ? [add 3 4] : 5")) "zero 0 ? [add 3 4] : 5") ;; Add more specific tests here, ;; if you want things more specific that provided via adding to `all-tests` below. (define e0 "43") (define e1 "<43>") (define e2 "[add 4 3]") (define e3 "<<[add 4 <3>]>>") (define e4 "[add <43> [mul 42 3]]") ;;; we can automate checking that string->expr is the (right)inverses of expr->string: (for-each (λ(e) (check-equal? (expr->string (string->expr e)) e)) (list e0 e1 e2 e3 e4)) ; `for-each` is like map except that it discards the result from each function-call; ; it is suitable for functions which are called solely for a side-effect. ; (`test-all` is such a function.) ;;; Though we also want to check that e0..e4 eval to 43,43,7,7,169 respectively. (for-each (λ(e v) (check-equal? (eval (string->expr e)) v)) ; is the source-Expression; v for Value (list e0 e1 e2 e3 e4) (list 43 43 7 7 169)) ;;; The above is a promising start, to automating tests. ;;; Okay, we'll generalize the above to a more complete test-harness. ;;; One thing, is that we don't want to have two parallel-lists; ;;; instead keep a list of pairs. ;;; Three sorts of tests we want to make, for many different exprs: (check-equal? (string->expr "[add 4 3]") (make-binop "add" 4 3)) (check-equal? (eval (string->expr "[add 4 3]")) 7) (check-equal? (expr->string (string->expr "[add 4 3]")) "[add 4 3]") ; Data Def'n: a `Z-example` is a list of length two or length three: ; (list ) (where is the expected result `(eval (string->expr ))`, OR ; (list ) (where is the expected result `(string->expr )`) ; ; If *should* throw an error (e.g. 'unbound identifier' or 'divide by 0'), then: ; `` may also be one of: ; - a function of one argument (an error-handler) ; - a function of zero arguments (as in `check-error`) ; - "error" (as a symbol or string, w/ more letters after those 5 allowed); ; In these cases `test-eval` will give an error only if `(eval (string->expr ))` does NOT give an error. ; The error-handler (if provided) will be called; if it returns #t then the test-harness won't count it ; as an error. ; all-tests : (list-of Z-example) ; The last line of this file runs two-to-three tests on each Z-example. ; ; BE AWARE of the comma preceding the constructors; it's necessary to actually call it. ; See explanation at http://www.radford.edu/~itec380/2021fall-ibarland/Lectures/backquote.html ; (define all-tests `{("7" 7 7) ("<3>" 3 ,(make-paren 3)) ("[add 3 4]" 7 ,(make-binop "add" 3 4)) ("[mul 3 4]" 12 ,(make-binop "mul" 3 4 )) ("[add [add 3 4] [mul 3 4]]" 19) ("[mul <3> <[add 2 3]>]" 15) ("zero 0 ? 1 : 2" 1 ,(make-if-zero 0 1 2)) ("zero 1 ? 1 : 2" 2 ,(make-if-zero 1 1 2)) ("zero [add 3 -3] ? 1 : 2" 1 ,(make-if-zero (make-binop "add" 3 -3) 1 2)) ("zero [add zero zero 0 ? 1 : 2 ? 3 : 4 -3] ? 1 : 2" 2 ,(make-if-zero (make-binop "add" (make-if-zero (make-if-zero 0 1 2) 3 4) -3) 1 2)) #| ;>>>Z1 tests ; Uncomment these tests, once `mod` is implemented: ("[mod 3 4]" 3) ("[mod [add 5 6] 3]" 2) ("[mod 8.1 3]" 2.1) ("[mod 8 3.1]" 1.8) ("[mod -8.1 3]" 0.9) ("[mod -8 3.1]" 1.3) ("[mod 8.1 -3]" -0.9) ("[mod 8 -3.1]" -1.3) ("[mod -8.1 -3]" -2.1) ("[mod -8 -3.1]" -1.8) ("[mod 8 2]" 0) ("[mod -8 2]" 0) ("[mod 8 -2]" 0) ("[mod -8 -2]" 0) ("[mod 8 3]" 2) ("[mod -8 3]" 1) ("[mod 8 -3]" -1) ("[mod -8 -3]" -2) YOU-MUST-CREATE-SOME-TESTS-FOR-IfGrtr's |# }) ; ; For info on backquote, see documentation and/or: ; http://www.radford.edu/itec380/2021fall-ibarland/Lectures/backquote.html ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; helper functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; The following functions should really be in a separate file, and exported from there. ;; However, putting this in to a file 'Zi-test-harness.rkt' would become mildly problematic: ;; since it calls 'eval', 'string->expr' as provided in Z0, it needs to require Z0.rkt. ;; As we update our implementation Z0.rkt to Z2.rkt,Z4.rkt etc, ;; we'd then need to update *this* file each time, changing *nothing* but the 'require'. Yuck. ;; An actual solution would be using "units", where when we call `require` we "pass in" the dependencies: ;; http://docs.racket-lang.org/reference/creatingunits.html?q=unit#%28form._%28%28lib._racket%2Funit..rkt%29._unit%29%29 ;; ;; But rather than add that level of indirection for a student-assignment, we'll just repeat ;; this code inside each Zi-test.rkt. ; my-check-equal? : any, any, string -> boolean ; If the two values aren't equal, print an error message. ; (Nothing prints on success; that is better done at a higher level, in `test-all`.) ; >>>Uses the global-variable `prog#`. ; (define (my-check-equal? actual expected err-msg) (let {[result (equal? actual expected)]} (begin (when (not result) (printf "~ntest-program #~a failed:\n~a\n" prog# err-msg)) result))) ; test-internal-representation : Zi-example -> boolean ; Test that t parses to the correct internal tree-representation (if provided) ; (define (test-internal-representation t) (or (< (length t) 3) ; if no internal-rep provided, we pass the test! (with-handlers {[exn:fail? (print-exception t 'parse)]} (my-check-equal? (string->expr (first t)) (third t) (format "Parsing ~v\nresulted in ~v\ninstead of ~v\nas expected." (first t) (string->expr (first t)) (third t)))))) ; normalize-expected-value : Zi-example -> (or/c number? struct? string? procedure?) ; Just return the expected-value from the Zi-example -- the second field. ; BUT we also do some extra work to support "error results": if the expected-result was… ; - …a function expecting 1 arg, return it (presumably it's an exception handler). ; - …a function expecting 0 args, return it as an exception-handler-that-ignores-its-input; cf. `check-error. ; - …a symbol or string starting with the letters "error", return an exception-handler that just returns #t. ; (define (normalize-expected-eval t) (let* {[e (second t)]} (cond [(number? e) e] ; the expected result [(struct? e) e] ; the expected result (presumably some sort of func-expr) ; Now, look for "error handlers", when the (eval (first t)) is *desired* to fail -- ; E.g. an unbound identifier or divide-by-0. [(and (or (symbol? e) (string? e)) (regexp-match? #px"^(?i:error).*" (if (symbol? e) (symbol->string e) e))) (λ(_) #t)] ; an exception-handler that just swallows the exception and returns #t. [(and (procedure? e) (procedure-arity-includes? e 1)) e] ; an exception-handler [(and (procedure? e) (procedure-arity-includes? e 0)) (λ(_) (e))] ; convert a thunk to an exception-handler ; Finally, we go to great lengths in case ; the Zi-example was quoted-inside-quasiquote: `(... ("someProg" 'error) ...) [(and (cons? e) (equal? (first e) 'quote) (cons? (rest e)) (symbol? (second e)) (regexp-match? #px"^(?i:error).*" (symbol->string (second e)))) (λ(_) #t)] [else e] ; pass-through anything else; if `test-eval` is being called, ; presumably it *won't* match the expected-result, failing `test-eval`. ))) (define struct:2*3 (make-binop "mul" 2 3)) (check-equal? (normalize-expected-eval `("someProg" 17)) 17) (check-equal? (normalize-expected-eval `("someProg" 17 ,struct:2*3)) 17) (check-equal? (normalize-expected-eval `("someProg" ,struct:2*3)) struct:2*3) (check-equal? (normalize-expected-eval `("someProg" ,struct:2*3 ,struct:2*3)) struct:2*3) ; if the second-item is the string/symbol "error" (or just starts with that), ; then normalize-expected-eval returns an error-handler. Call it: (check-equal? ((normalize-expected-eval `("someProg" "error")) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" "error" ,struct:2*3)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" "error-ho!")) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" "erRoR, eh?" ,struct:2*3)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" error)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" error ,struct:2*3)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" error-ho)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" erRoR-eh? ,struct:2*3)) "a-mock-exception") #t) ; (The following are *double* quoting the symbol, but our code tries to handle it ; (not a good design choice, but meant to keep a student from banging their head ; for 30min+ if they don't realize they have an extra quote):) (check-equal? ((normalize-expected-eval `("someProg" 'error)) "a-mock-exception") #t) (check-equal? ((normalize-expected-eval `("someProg" 'error ,struct:2*3)) "a-mock-exception") #t) ; The second-item can also be a function-value. ; (Here, the unquoting is necessary (since we don't heroically/misguidedly try to fix it here).) (check-equal? ((normalize-expected-eval `("someProg" ,(λ(v) 17))) "a-mock-exception") 17) (check-equal? ((normalize-expected-eval `("someProg" ,(λ(v) 17) ,struct:2*3)) "a-mock-exception") 17) (check-equal? ((normalize-expected-eval `("someProg" ,(λ() 17))) "a-mock-exception") 17) (check-equal? ((normalize-expected-eval `("someProg" ,(λ() 17) ,struct:2*3)) "a-mock-exception") 17) ; test-eval : Zi-example -> boolean ; Test that the Zi-example `eval`s to what it should. ; (define (test-eval t) (with-handlers {[exn:fail? (if (procedure? (normalize-expected-eval t)) (normalize-expected-eval t) (print-exception t 'eval))]} (my-check-equal? (eval (string->expr (first t))) (second t) (format "Program ~v\neval'd to ~v\ninstead of ~v\nas expected." (first t) (eval (string->expr (first t))) (second t))))) ; test-parse-inverse-of-to-string : Zi-example -> void? ; Test that `parse` and `expr->string` are inverses of each other: ; `parse` is a right-inverse: for a string `s`, (expr->string (parse s)) = s, and ; `parse` is a left- inverse: for a tree `expr`, (parse (expr->string expr)) = expr. ; Note that spaces between tokens in a string is ignored, so they're not *quite* exact inverses. ; ; Also, other tests are redundant with checking the left-inverse, ; but we still check it to be independent of other code. ; (define (test-parse-inverse-of-to-string t) (and (with-handlers {[exn:fail? (print-exception t 'parse-then-tostring)]} (my-check-equal? (string->tokens (expr->string (string->expr (first t)))) (string->tokens (first t)) (format "Parsing ~v then converting back to string gave ~v." (first t) (expr->string (string->expr (first t)))))) (or (< (length t) 3) ; don't call it failure, if we don't have info to do further test! (with-handlers {[exn:fail? (print-exception t 'tostring-then-parse)]} (my-check-equal? (string->expr (expr->string (third t))) (third t) (format "Converting ~v to string and re-parsing it gave ~v." (third t) (expr->string (third t)))))))) ; test-one-prog-2-4-ways : Zi-example -> void? ; Make sure that t meets the following properties: ; i. Parsing the string results in the expected internal representation (*) ; ii. Check that parsing the string and then to-string'ing the result ; gives back the initial string ; iii. Check that to-string'ing the internal representation and then parsing ; that resulting string gives back the initial internal representation (*) ; iv. check that eval'ing the (parsed) string gives the expected value. ; ; (*) steps i,iii can only be performed if the Zi-example contained all three values. ; If it only contained a string and a value, then only *two* tests get performed. ; This affects the test-number reported, should a later test fail. ; (define prog# 0) (define (test-one-prog-2-4-ways t) (begin (set! prog# (add1 prog#)) (printf ".") (begin0 (and (test-internal-representation t) (test-parse-inverse-of-to-string t) ; N.B. counts as two tests (test-eval t)) (when (zero? (remainder prog# 5)) (printf " "))))) (define exceptions-seen 0) (define (print-exception t where) (λ(exn) (begin (set! exceptions-seen (add1 exceptions-seen)) (printf "~nEXCEPTION: ~a~nOccurred while trying to ~a test-program #~a: ~v~n" (exn-message exn) where prog# (first t)) #f))) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; run the tests ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; (printf "Running Z-text-harness~n") (define test-results (map test-one-prog-2-4-ways all-tests)) ; This line actually invokes the checker (define n (length test-results)) (define fails (length (filter false? test-results))) (define passes (length (filter (λ(x) (equal? x #true)) test-results))) (if (zero? n) (printf "Please add Z0 test-cases to `all-tests`.") (printf "~nZ-test-harness done: ~v/~v (~v%) Z0 programs passed 2-to-4 checks each; ~a.~n" passes n (floor (* 100 (/ passes n))) (if (zero? fails) "nice" (format "~v Z0 programs failed" fails)))) ;; a line which just "re"prints out the tests, ;; except with the *actual* (not expected) results of eval, string->expr. ;; #;(pretty-print (map (λ(tst) (let* {[prog (string->expr (first tst))]} (list (expr->string prog) (eval prog)))) all-tests)) #| @author ibarland@radford.edu @version 2021-Nov-08 @original-at http://www.radford.edu/itec380/2021fall-ibarland/Homeworks/Project/Z0-tests.rkt @license CC-BY -- share/adapt this file freely, but include attribution, thx. https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/legalcode Including a link to the *original* file satisifies "appropriate attribution". |#