Create some unit tests for Virtual Machine

MVM.cabal

@@ -64,6 +64,7 @@ test-suite spec
       transformers ^>=0.5.6.2,
       hspec ==2.*
   other-modules:      
+      VirtualMachineSpec
       Assembler.TokenizerSpec  
       Assembler.ParserSpec
       Assembler.EmitterSpec
@@ -72,6 +73,7 @@ test-suite spec
       VirtualMachine.VM
       VirtualMachine.Instruction
       VirtualMachine.Interpreter
+      Assembler.Compiler
       Assembler.Tokenizer
       Assembler.Parser
       Assembler.Emitter

test/VirtualMachineSpec.hs

@@ -0,0 +1,614 @@
+module VirtualMachineSpec where
+
+import Test.Hspec
+import qualified Data.Sequence as S
+
+
+import VirtualMachine.VM (VM(..), empty)
+import Runner (run)
+
+done :: [Int] -> Int -> Int -> Either String VM
+done stack pc fp = return $ empty { _stack = S.fromList stack, _pc = pc, _fp = fp, _halt = True }
+
+spec :: Spec
+spec = do
+  describe "nop" $ do
+    it "does do nothing" $ do
+      let input = "nop\n\
+                  \halt"
+      let expected = done [] 1 (-1)
+      actual <- run input
+      actual `shouldBe` expected
+  
+  describe "halt" $ do
+    it "shutdowns the VM" $ do
+      let input = "halt"
+      let expected = done [] 0 (-1)
+      actual <- run input
+      actual `shouldBe` expected      
+    it "throws an error if halt instruction is not encountered and program exits" $ do
+      let input = "nop\n\
+                  \nop"
+      let expected = Left "PC (=2) exceeds program size (=2)"
+      actual <- run input
+      actual `shouldBe` expected        
+
+  describe "push" $ do
+    it "supports push" $ do
+      let input = "push 1\n\
+                  \halt"
+      let expected = done [1] 2 (-1)
+      actual <- run input
+      actual `shouldBe` expected
+    it "supports pushing in the correct order" $ do
+      let input = "push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \push 4\n\
+                  \halt"
+      let expected = done [4, 3, 2, 1] 8 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+  
+  describe "pop" $ do
+    it "supports pop" $ do
+      let input = "push 1\n\
+                  \pop\n\
+                  \halt"
+      let expected = done [] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected
+    it "supports poping in correct order" $ do
+      let input = "push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \push 4\n\
+                  \pop\n\
+                  \pop\n\
+                  \halt"
+      let expected = done [2, 1] 10 (-1)
+      actual <- run input
+      actual `shouldBe` expected
+    it "raises error if empty stack" $ do
+      let input = "pop\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected     
+
+  describe "dup" $ do
+    it "duplicates the top stack value" $ do
+      let input = "push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \dup\n\
+                  \halt"
+      let expected = done [3, 3, 2, 1] 7 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "raises error if empty stack" $ do
+      let input = "dup\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected       
+
+  describe "swap" $ do
+    it "swaps the top 2 stack values" $ do
+      let input = "push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \push 4\n\
+                  \push 5\n\
+                  \swap\n\
+                  \halt"
+      let expected = done [4, 5, 3, 2, 1] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "raises error if empty stack" $ do
+      let input = "swap\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected           
+    it "raises error if stack is not big enough" $ do
+      let input = "push 5\n\
+                  \swap\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 1"
+      actual <- run input
+      actual `shouldBe` expected      
+
+  describe "add" $ do
+    it "sums the top 2 stack values" $ do
+      let input = "push 7\n\
+                  \push 4\n\
+                  \add\n\
+                  \halt"
+      let expected = done [7+4] 5 (-1)
+      actual <- run input
+      actual `shouldBe` expected        
+    it "can be composed" $ do
+      let input = "push 4\n\
+                  \push 7\n\
+                  \push 10\n\
+                  \push 3\n\
+                  \add\n\
+                  \add\n\
+                  \add\n\
+                  \halt"
+      let expected = done [4+(7+(10+3))] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected      
+    it "raises error if empty stack" $ do
+      let input = "add\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected           
+    it "raises error if stack is not big enough" $ do
+      let input = "push 5\n\
+                  \add\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 1"
+      actual <- run input
+      actual `shouldBe` expected        
+
+  describe "sub" $ do
+    it "substracts the top 2 stack values" $ do
+      let input = "push 7\n\
+                  \push 4\n\
+                  \sub\n\
+                  \halt"
+      let expected = done [7-4] 5 (-1)
+      actual <- run input
+      actual `shouldBe` expected        
+    it "can be composed" $ do
+      let input = "push 4\n\
+                  \push 7\n\
+                  \push 10\n\
+                  \push 3\n\
+                  \sub\n\
+                  \sub\n\
+                  \sub\n\
+                  \halt"
+      let expected = done [4-(7-(10-3))] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected      
+    it "raises error if empty stack" $ do
+      let input = "sub\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected           
+    it "raises error if stack is not big enough" $ do
+      let input = "push 5\n\
+                  \sub\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 1"
+      actual <- run input
+      actual `shouldBe` expected   
+
+  describe "mul" $ do
+    it "multiplies the top 2 stack values" $ do
+      let input = "push 7\n\
+                  \push 4\n\
+                  \mul\n\
+                  \halt"
+      let expected = done [7*4] 5 (-1)
+      actual <- run input
+      actual `shouldBe` expected        
+    it "can be composed" $ do
+      let input = "push 4\n\
+                  \push 7\n\
+                  \push 10\n\
+                  \push 3\n\
+                  \mul\n\
+                  \mul\n\
+                  \mul\n\
+                  \halt"
+      let expected = done [4*(7*(10*3))] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected      
+    it "raises error if empty stack" $ do
+      let input = "mul\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected           
+    it "raises error if stack is not big enough" $ do
+      let input = "push 5\n\
+                  \mul\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 1"
+      actual <- run input
+      actual `shouldBe` expected    
+
+  describe "div" $ do
+    it "divides the top 2 stack values" $ do
+      let input = "push 7\n\
+                  \push 4\n\
+                  \div\n\
+                  \halt"
+      let expected = done [7 `div` 4] 5 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "can be composed" $ do
+      let input = "push 4\n\
+                  \push 7\n\
+                  \push 10\n\
+                  \push 3\n\
+                  \div\n\
+                  \div\n\
+                  \div\n\
+                  \halt"
+      let expected = done [4 `div` (7 `div` (10 `div` 3))] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected      
+    it "raises error if empty stack" $ do
+      let input = "div\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected           
+    it "raises error if stack is not big enough" $ do
+      let input = "push 5\n\
+                  \div\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 2 elements, got 1"
+      actual <- run input
+      actual `shouldBe` expected  
+
+  describe "neg" $ do
+    it "negates the top stack value" $ do
+      let input = "push 4\n\
+                  \neg\n\
+                  \halt"
+      let expected = done [-4] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "the od number of 'neg' instructions should negate the value" $ do
+      let input = "push 4\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \halt"
+      let expected = done [4] 8 (-1)
+      actual <- run input
+      actual `shouldBe` expected         
+    it "the even number of 'neg' instructions should not change the value" $ do
+      let input = "push 4\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\
+                  \neg\n\                  
+                  \halt"
+      let expected = done [-4] 7 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "neg\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected         
+
+  describe "not" $ do
+    it "negates the 'true' value" $ do
+      let input = "push 1\n\
+                  \not\n\
+                  \halt"
+      let expected = done [0] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "negates the 'false' value" $ do
+      let input = "push 0\n\
+                  \not\n\
+                  \halt"
+      let expected = done [1] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected         
+    it "negates any non-zero value to false" $ do
+      let input = "push 129\n\
+                  \not\n\
+                  \halt"
+      let expected = done [0] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected          
+    it "the od number of 'neg' instructions should negate the logic value" $ do
+      let input = "push 1\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \halt"
+      let expected = done [1] 8 (-1)
+      actual <- run input
+      actual `shouldBe` expected         
+    it "the even number of 'neg' instructions should not change the value" $ do
+      let input = "push 1\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\
+                  \not\n\                  
+                  \halt"
+      let expected = done [0] 7 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "not\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected            
+
+  describe "jmp" $ do
+    it "changes the program counter register" $ do
+      let input = "nop\n\
+                  \jmp 4\n\
+                  \halt\n\
+                  \nop\n\
+                  \nop\n\
+                  \jmp 3"
+      let expected = done [] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected        
+    it "skips instructions after jump" $ do
+      let input = "nop\n\
+                  \jmp 11\n\
+                  \push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \push 4\n\
+                  \halt"
+      let expected = done [] 11 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "supports jumping by labels" $ do
+      let input = "nop\n\
+                  \jmp &end\n\
+                  \stop:\n\
+                  \halt\n\
+                  \push 1\n\
+                  \push 2\n\
+                  \push 3\n\
+                  \push 4\n\
+                  \end: jmp &stop"
+      let expected = done [] 3 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+
+  describe "je" $ do
+    it "jumps if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \je &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "proceeds if top stack value != 0" $ do
+      let input = "push 1\n\
+                  \je &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "je 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected  
+             
+  describe "jne" $ do
+    it "jumps if top stack value != 0" $ do
+      let input = "push 4\n\
+                  \jne &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "proceeds if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \jne &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "jne 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected  
+
+  describe "jg" $ do
+    it "jumps if top stack value > 0" $ do
+      let input = "push 1\n\
+                  \jg &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "proceeds if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \jg &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "proceeds if top stack value < 0" $ do
+      let input = "push 1\n\
+                  \neg\n\
+                  \jg &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 7 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "jg 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected    
+  
+  describe "jl" $ do
+    it "proceeds if top stack value > 0" $ do
+      let input = "push 1\n\
+                  \jl &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "proceeds if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \jl &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "jumps if top stack value < 0" $ do
+      let input = "push 1\n\
+                  \neg\n\
+                  \jl &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 10 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "jl 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected 
+         
+  describe "jge" $ do
+    it "jumps if top stack value > 0" $ do
+      let input = "push 1\n\
+                  \jge &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "jumps if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \jge &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "proceeds if top stack value < 0" $ do
+      let input = "push 1\n\
+                  \neg\n\
+                  \jge &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 7 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "jge 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected
+
+  describe "jle" $ do
+    it "proceeds if top stack value > 0" $ do
+      let input = "push 1\n\
+                  \jle &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [0] 6 (-1)
+      actual <- run input
+      actual `shouldBe` expected  
+    it "jumps if top stack value == 0" $ do
+      let input = "push 0\n\
+                  \jle &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 9 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "jumps if top stack value < 0" $ do
+      let input = "push 1\n\
+                  \neg\n\
+                  \jle &jumped\n\
+                  \push 0\n\
+                  \halt\n\
+                  \jumped:\n\
+                  \push 1\n\
+                  \halt"
+      let expected = done [1] 10 (-1)
+      actual <- run input
+      actual `shouldBe` expected   
+    it "raises error if empty stack" $ do
+      let input = "jle 0\n\
+                  \halt"
+      let expected = Left "Attempt to pop from empty stack: tried to pop 1 elements, got 0"
+      actual <- run input
+      actual `shouldBe` expected