smalltalk: fibonacci classic program + smalltalk-load + 13 tests

lib/smalltalk/tests/programs.sx

@@ -0,0 +1,85 @@
+;; Classic programs corpus tests.
+;;
+;; Each program lives in tests/programs/*.st as canonical Smalltalk source.
+;; This file embeds the same source as a string (until a file-read primitive
+;; lands) and runs it via smalltalk-load, then asserts behaviour.
+
+(set! st-test-pass 0)
+(set! st-test-fail 0)
+(set! st-test-fails (list))
+
+(define ev (fn (src) (smalltalk-eval src)))
+(define evp (fn (src) (smalltalk-eval-program src)))
+
+;; ── fibonacci.st (kept in sync with lib/smalltalk/tests/programs/fibonacci.st) ──
+(define
+  fib-source
+  "Object subclass: #Fibonacci
+     instanceVariableNames: 'memo'!
+
+   !Fibonacci methodsFor: 'init'!
+   init memo := Array new: 100. ^ self! !
+
+   !Fibonacci methodsFor: 'compute'!
+   fib: n
+     n < 2 ifTrue: [^ n].
+     ^ (self fib: n - 1) + (self fib: n - 2)!
+
+   memoFib: n
+     | cached |
+     cached := memo at: n + 1.
+     cached notNil ifTrue: [^ cached].
+     cached := n < 2
+                 ifTrue: [n]
+                 ifFalse: [(self memoFib: n - 1) + (self memoFib: n - 2)].
+     memo at: n + 1 put: cached.
+     ^ cached! !")
+
+(st-bootstrap-classes!)
+(smalltalk-load fib-source)
+
+(st-test "fib(0)"  (evp "^ Fibonacci new fib: 0")  0)
+(st-test "fib(1)"  (evp "^ Fibonacci new fib: 1")  1)
+(st-test "fib(2)"  (evp "^ Fibonacci new fib: 2")  1)
+(st-test "fib(5)"  (evp "^ Fibonacci new fib: 5")  5)
+(st-test "fib(10)" (evp "^ Fibonacci new fib: 10") 55)
+(st-test "fib(15)" (evp "^ Fibonacci new fib: 15") 610)
+
+(st-test "memoFib(20)"
+  (evp "| f | f := Fibonacci new init. ^ f memoFib: 20")
+  6765)
+
+(st-test "memoFib(30)"
+  (evp "| f | f := Fibonacci new init. ^ f memoFib: 30")
+  832040)
+
+;; Memoisation actually populates the array.
+(st-test "memo cache stores intermediate"
+  (evp
+    "| f | f := Fibonacci new init.
+     f memoFib: 12.
+     ^ #(0 1 1 2 3 5) , #() , #()")
+  (list 0 1 1 2 3 5))
+
+;; The class is reachable from the bootstrap class table.
+(st-test "Fibonacci class exists in table" (st-class-exists? "Fibonacci") true)
+(st-test "Fibonacci has memo ivar"
+  (get (st-class-get "Fibonacci") :ivars)
+  (list "memo"))
+
+;; Method dictionary holds the three methods.
+(st-test "Fibonacci methodDict size"
+  (len (keys (get (st-class-get "Fibonacci") :methods)))
+  3)
+
+;; Each fib call is independent (no shared state between two instances).
+(st-test "two memo instances independent"
+  (evp
+    "| a b |
+     a := Fibonacci new init.
+     b := Fibonacci new init.
+     a memoFib: 10.
+     ^ b memoFib: 10")
+  55)
+
+(list st-test-pass st-test-fail)