From f97bd84050489c0da47876d1482c1e532d0365be Mon Sep 17 00:00:00 2001
From: James Eversole <jameseversole@imarc.com>
Date: Mon, 27 Jan 2025 16:03:03 -0600
Subject: [PATCH] Adds basic tests for modules

Basic tests for modules. Fixes for parsing multiple import statements.
---
 README.md              |  3 ++-
 src/Parser.hs          |  6 +++++-
 test/Spec.hs           | 42 ++++++++++++++++++++++++++++++++++++++++--
 test/lambda-A.tri      |  2 ++
 test/multi-level-A.tri |  3 +++
 test/multi-level-B.tri |  3 +++
 test/multi-level-C.tri |  2 ++
 test/namespace-A.tri   |  3 +++
 test/namespace-B.tri   |  2 ++
 test/unresolved-A.tri  |  2 ++
 test/vars-A.tri        |  7 +++++++
 test/vars-B.tri        |  2 ++
 test/vars-C.tri        |  2 ++
 13 files changed, 75 insertions(+), 4 deletions(-)
 create mode 100644 test/lambda-A.tri
 create mode 100644 test/multi-level-A.tri
 create mode 100644 test/multi-level-B.tri
 create mode 100644 test/multi-level-C.tri
 create mode 100644 test/namespace-A.tri
 create mode 100644 test/namespace-B.tri
 create mode 100644 test/unresolved-A.tri
 create mode 100644 test/vars-A.tri
 create mode 100644 test/vars-B.tri
 create mode 100644 test/vars-C.tri

diff --git a/README.md b/README.md
index 720326f..2bc3594 100644
--- a/README.md
+++ b/README.md
@@ -10,12 +10,13 @@ tricu is the word for "tree" in Lojban: `(x1) is a tree of species/cultivar (x2)
 
 - Tree Calculus operator: `t`
 - Assignments: `x = t t`
+- Immutabile definitions
 - Lambda abstraction syntax: `id = (\a : a)`
 - List, Number, and String literals: `[(2) ("Hello")]` 
 - Function application: `not (not false)`
 - Higher order/first-class functions: `map (\a : lconcat a "!") [("Hello")]`
 - Intensionality blurs the distinction between functions and data (see REPL examples)
-- Immutability
+- Simple module system for code organization
 
 ## REPL examples
 
diff --git a/src/Parser.hs b/src/Parser.hs
index ca68488..dd8dd85 100644
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -76,12 +76,16 @@ parseProgramM = do
   skipMany topLevelNewline
   moduleNode <- optional parseModuleM
   skipMany topLevelNewline
-  importNodes <- many parseImportM
+  importNodes <- many (do
+    node <- parseImportM
+    skipMany topLevelNewline
+    return node)
   skipMany topLevelNewline
   exprs <- sepEndBy parseOneExpression (some topLevelNewline)
   skipMany topLevelNewline
   return (maybe [] (: []) moduleNode ++ importNodes ++ exprs)
 
+
 parseModuleM :: ParserM TricuAST
 parseModuleM = do
   LModule moduleName <- satisfyM isModule
diff --git a/test/Spec.hs b/test/Spec.hs
index d062b1c..7c8f102 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -7,12 +7,13 @@ import Parser
 import REPL
 import Research
 
-import Control.Exception (evaluate, try, SomeException)
+import Control.Exception      (evaluate, try, SomeException)
 import Control.Monad.IO.Class (liftIO)
+import Data.List              (isInfixOf)
 import Test.Tasty
 import Test.Tasty.HUnit
 import Test.Tasty.QuickCheck
-import Text.Megaparsec (runParser)
+import Text.Megaparsec        (runParser)
 
 import qualified Data.Map as Map
 import qualified Data.Set as Set
@@ -31,6 +32,7 @@ tests = testGroup "Tricu Tests"
   , lambdas
   , baseLibrary
   , fileEval
+  , modules
   , demos
   ]
 
@@ -498,6 +500,42 @@ fileEval = testGroup "File evaluation tests"
       decodeResult (result res) @?= "\"String test!\""
   ]
 
+modules :: TestTree
+modules = testGroup "Test modules"
+  [ testCase "Detect cyclic dependencies" $ do
+      result <- try (liftIO $ evaluateFileResult "./test/cycle-1.tri") :: IO (Either SomeException T)
+      case result of
+        Left e -> do
+          let errorMsg = show e
+          if "Encountered cyclic import" `isInfixOf` errorMsg
+            then return ()
+            else assertFailure $ "Unexpected error: " ++ errorMsg
+        Right _ -> assertFailure "Expected cyclic dependencies"
+  , testCase "Module imports and namespacing" $ do
+      res <- liftIO $ evaluateFileResult "./test/namespace-A.tri"
+      res @?= Leaf
+  , testCase "Multiple imports" $ do
+      res <- liftIO $ evaluateFileResult "./test/vars-A.tri"
+      res @?= Leaf
+  , testCase "Error on unresolved variable" $ do
+      result <- try (liftIO $ evaluateFileResult "./test/unresolved-A.tri") :: IO (Either SomeException T)
+      case result of
+        Left e -> do
+          let errorMsg = show e
+          if "undefinedVar" `isInfixOf` errorMsg
+            then return ()
+            else assertFailure $ "Unexpected error: " ++ errorMsg
+        Right _ -> assertFailure "Expected unresolved variable error"
+  , testCase "Multi-level imports" $ do
+      res <- liftIO $ evaluateFileResult "./test/multi-level-A.tri"
+      res @?= Leaf
+  , testCase "Lambda expression namespaces" $ do
+      res <- liftIO $ evaluateFileResult "./test/lambda-A.tri"
+      res @?= Leaf
+  ]
+
+
+-- All of our demo tests are also module tests
 demos :: TestTree
 demos = testGroup "Test provided demo functionality"
   [ testCase "Structural equality demo" $ do
diff --git a/test/lambda-A.tri b/test/lambda-A.tri
new file mode 100644
index 0000000..844f615
--- /dev/null
+++ b/test/lambda-A.tri
@@ -0,0 +1,2 @@
+!module A
+main = (\x : x) t
diff --git a/test/multi-level-A.tri b/test/multi-level-A.tri
new file mode 100644
index 0000000..34a85f2
--- /dev/null
+++ b/test/multi-level-A.tri
@@ -0,0 +1,3 @@
+!module A
+!import "./test/multi-level-B.tri" B
+main = B.main
diff --git a/test/multi-level-B.tri b/test/multi-level-B.tri
new file mode 100644
index 0000000..0d92637
--- /dev/null
+++ b/test/multi-level-B.tri
@@ -0,0 +1,3 @@
+!module B
+!import "./test/multi-level-C.tri" C
+main = C.val
diff --git a/test/multi-level-C.tri b/test/multi-level-C.tri
new file mode 100644
index 0000000..a4005fb
--- /dev/null
+++ b/test/multi-level-C.tri
@@ -0,0 +1,2 @@
+!module C
+val = t
diff --git a/test/namespace-A.tri b/test/namespace-A.tri
new file mode 100644
index 0000000..6185d67
--- /dev/null
+++ b/test/namespace-A.tri
@@ -0,0 +1,3 @@
+!module A
+!import "./test/namespace-B.tri" B
+main = B.x
diff --git a/test/namespace-B.tri b/test/namespace-B.tri
new file mode 100644
index 0000000..2cda9a7
--- /dev/null
+++ b/test/namespace-B.tri
@@ -0,0 +1,2 @@
+!module B
+x = t
diff --git a/test/unresolved-A.tri b/test/unresolved-A.tri
new file mode 100644
index 0000000..ca19217
--- /dev/null
+++ b/test/unresolved-A.tri
@@ -0,0 +1,2 @@
+!module A
+main = undefinedVar
diff --git a/test/vars-A.tri b/test/vars-A.tri
new file mode 100644
index 0000000..962def7
--- /dev/null
+++ b/test/vars-A.tri
@@ -0,0 +1,7 @@
+!module A
+
+!import "./test/vars-B.tri" B
+
+!import "./test/vars-C.tri" C
+
+main = B.y (C.z)
diff --git a/test/vars-B.tri b/test/vars-B.tri
new file mode 100644
index 0000000..b72ee50
--- /dev/null
+++ b/test/vars-B.tri
@@ -0,0 +1,2 @@
+!module B
+y = \x : x
diff --git a/test/vars-C.tri b/test/vars-C.tri
new file mode 100644
index 0000000..78d36ce
--- /dev/null
+++ b/test/vars-C.tri
@@ -0,0 +1,2 @@
+!module C
+z = t