Add more unit tests for Virtual Machine #3

This commit is contained in:
2021-11-10 22:38:54 +01:00
parent d32c2fa94a
commit f84e10a019
2 changed files with 120 additions and 9 deletions

View File

@@ -110,7 +110,7 @@ load vm (index:_) _ = do
let stack = _stack vm
let stackSize = S.length stack
val <- except $ evalState (runExceptT (getAt (stackSize - fp + index) ("Index " ++ (show index) ++ "out of stack bounds") )) vm
val <- except $ evalState (runExceptT (getAt (stackSize - fp + index) ("Index " ++ (show index) ++ " out of stack bounds") )) vm
return $ execState (push [val] >> forward 2) vm
load _ [] _ = except $ Left $ "Local parameter index expected"

View File

@@ -622,7 +622,7 @@ spec = do
\ halt \n\
\ fun: halt "
-- ┌────┬─ fp points to the beginning of active stack frame
-- 1 0 │
-- stack indexes: 1 0 │
-- │ │
let expected = done [4, -1] 6 0
-- ├───┤
@@ -644,7 +644,7 @@ spec = do
\ call &h \n\
\ h: halt "
-- ┌──────────────────────┬─ fp points to the beginning of active stack frame
-- 6 5 4 3 2 1 0 │
-- stack indexes: 6 5 4 3 2 1 0 │
-- │ │
let expected = done [14, 3, 10, 0, 1, 3, -1] 14 5
-- ├──┤ ├──┤ │ ├───┤
@@ -700,17 +700,128 @@ spec = do
-- └───── fp = -1 means the root program: there are no stack frames on the stack
actual <- run input
actual `shouldBe` expected
it "raises error if not enou" $ do
it "raises error if there is no previous fp on the stack (stack is empty)" $ do
let vm = empty { _stack = S.fromList [], _fp = 0 }
let input = " ret \n\
\ halt "
let expected = Left "Cannot determine previous frame pointer (fp)"
let vm = empty { _stack = S.fromList [], _fp = 0 }
actual <- exec vm input
actual `shouldBe` expected
it "raises error if stack is not big enough" $ do
it "raises error if there is no return address on the stack (stack size is 1)" $ do
let vm = empty { _stack = S.fromList [-1], _fp = 0 }
let input = " ret \n\
\ halt "
let expected = Left "Cannot determine return address"
let vm = empty { _stack = S.fromList [-1], _fp = 0 }
actual <- exec vm input
actual `shouldBe` expected
describe "ld" $ do
it "should lift the function argument to the stack top" $ do
let input = " push 14 \n\
\ call &f \n\
\ nop \n\
\ f: ld 0 \n\
\ halt"
let expected = done [14, 4, -1, 14] 7 1
actual <- run input
actual `shouldBe` expected
it "should lift multiple function arguments to the stack top" $ do
let input = " push 14 \n\
\ push 11 \n\
\ push 4 \n\
\ call &f \n\
\ nop \n\
\ f: ld 2 \n\
\ ld 1 \n\
\ ld 0 \n\
\ halt"
let expected = done [4, 11, 14, 8, -1, 4, 11, 14] 15 3
actual <- run input
actual `shouldBe` expected
it "can be combined with 'call' and 'ret' to define a function" $ do
let input = " push 14 \n\
\ push 11 \n\
\ call &sum \n\
\ halt \n\
\ sum: ld 1 \n\
\ ld 0 \n\
\ add \n\
\ ret "
let expected = done [25, 11, 14] 6 (-1)
actual <- run input
actual `shouldBe` expected
it "raises error if stack is empty" $ do
let input = " ld 0 \n\
\ halt "
let expected = Left "Index 0 out of stack bounds"
let vm = empty { _stack = S.fromList [], _fp = 0 }
actual <- exec vm input
actual `shouldBe` expected
it "raises error if stack contains only previous fp" $ do
let vm = empty { _stack = S.fromList [-1], _fp = 0 }
let input = " ld 0 \n\
\ halt "
let expected = Left "Index 0 out of stack bounds"
actual <- exec vm input
actual `shouldBe` expected
it "raises error if stack contains only previous fp and return address" $ do
let vm = empty { _stack = S.fromList [2, -1], _fp = 0 }
let input = " ld 0 \n\
\ halt "
let expected = Left "Index 0 out of stack bounds"
actual <- exec vm input
actual `shouldBe` expected
it "loads the first (0) argument if stack contains only previous fp, return address and single argument" $ do
let vm = empty { _stack = S.fromList [2, -1, 3], _fp = 1 }
let input = " ld 0 \n\
\ halt "
let expected = done [3, 2, -1, 3] 2 1
actual <- exec vm input
actual `shouldBe` expected
it "raises error when accessint second (1) argument if stack contains only previous fp, return address and single argument" $ do
let vm = empty { _stack = S.fromList [2, -1, 3], _fp = 1 }
let input = " ld 1 \n\
\ halt "
let expected = Left "Index 1 out of stack bounds"
actual <- exec vm input
actual `shouldBe` expected
it "loads the 11th argument if it exists" $ do
-- ┌─────────────────────────────────────────────────┬── fp points the beginning of active stack frame
-- │ │
-- stack indexes: 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 │
-- │ │
let vm = empty { _stack = S.fromList [ 2, -1, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 ], _fp = 12 }
-- │ │
-- argument indexes (ld): └─ 0 1 2 3 4 5 6 7 8 9 10 11
-- └───── ld 11 results in pushing 0 on to the top of the stack
let input = " ld 11 \n\
\ halt "
let expected = done [0, 2, -1, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0] 2 12
actual <- exec vm input
actual `shouldBe` expected
describe "clr" $ do
it "wipes 4 values before the top of the stack" $ do
let input = " push 1 \n\
\ push 2 \n\
\ push 3 \n\
\ push 4 \n\
\ push 5 \n\
\ clr 4 \n\
\ halt "
let expected = done [5] 12 (-1)
actual <- run input
actual `shouldBe` expected
it "can be combined with 'call' and 'ret' to define a function and perform a clean by caller" $ do
let input = " push 14 \n\
\ push 11 \n\
\ call &sum \n\
\ clr 2 \n\
\ halt \n\
\ sum: ld 1 \n\
\ ld 0 \n\
\ add \n\
\ ret "
let expected = done [25] 8 (-1)
actual <- run input
actual `shouldBe` expected