feat: semantic analysis + type checker (Phase 2)

tests/sema_test.nim

@@ -0,0 +1,85 @@
+import std/[unittest, strutils]
+import ../src/[lexer, parser, sema, types]
+
+proc checkSource(source: string): SemaResult =
+  let lexRes = tokenize(source, "<test>")
+  check not lexRes.hasErrors
+  let parseRes = parse(lexRes.tokens, "<test>")
+  check parseRes.diagnostics.len == 0
+  result = analyze(parseRes.module)
+
+suite "Sema":
+  test "valid function with correct types":
+    let res = checkSource("func Main() -> int { return 0; }")
+    check not res.hasErrors
+
+  test "undeclared identifier":
+    let res = checkSource("func Main() -> int { return x; }")
+    check res.hasErrors
+    check "undeclared" in res.diagnostics[0].message
+
+  test "duplicate function":
+    let res = checkSource("func Main() -> int { return 0; } func Main() -> int { return 1; }")
+    check res.hasErrors
+    check "duplicate" in res.diagnostics[0].message
+
+  test "type mismatch in assignment":
+    let res = checkSource("func Main() -> int { let x: int32 = c8\"hello\"; return 0; }")
+    check res.hasErrors
+    check "cannot assign" in res.diagnostics[0].message
+
+  test "valid arithmetic":
+    let res = checkSource("func Main() -> int { return 1 + 2 * 3; }")
+    check not res.hasErrors
+
+  test "arithmetic on strings fails":
+    let res = checkSource("func Main() -> int { return c8\"a\" + c8\"b\"; }")
+    check res.hasErrors
+
+  test "valid function call":
+    let res = checkSource("func Add(a: int, b: int) -> int { return a + b; } func Main() -> int { return Add(1, 2); }")
+    check not res.hasErrors
+
+  test "wrong number of arguments":
+    let res = checkSource("func Add(a: int32, b: int32) -> int32 { return a + b; } func Main() -> int { return Add(1); }")
+    check res.hasErrors
+    check "expected 2 arguments" in res.diagnostics[0].message
+
+  test "wrong argument type":
+    let res = checkSource("func Add(a: int32, b: int32) -> int32 { return a + b; } func Main() -> int { return Add(c8\"a\", 2); }")
+    check res.hasErrors
+    check "argument 1" in res.diagnostics[0].message
+
+  test "if condition must be bool":
+    let res = checkSource("func Main() -> int { if 1 { return 0; } return 0; }")
+    check res.hasErrors
+    check "bool" in res.diagnostics[0].message
+
+  test "valid if with bool":
+    let res = checkSource("func Main() -> int { if true { return 0; } return 0; }")
+    check not res.hasErrors
+
+  test "pointer dereference":
+    let res = checkSource("func Main() -> int32 { let p: *int32 = null; return *p; }")
+    check not res.hasErrors
+
+  test "struct field access":
+    let res = checkSource("struct Point { x: float64; y: float64; } func Main() -> int32 { let p = Point { x: 1.0, y: 2.0 }; return 0; }")
+    check not res.hasErrors
+
+  test "unknown struct field":
+    let res = checkSource("struct Point { x: float64; y: float64; } func Main() -> int32 { let p = Point { x: 1.0, y: 2.0 }; return p.z; }")
+    check res.hasErrors
+    check "no field" in res.diagnostics[0].message
+
+  test "valid comparison":
+    let res = checkSource("func Main() -> int { return 1 == 2; }")
+    check not res.hasErrors
+
+  test "valid slice literal":
+    let res = checkSource("func Main() -> int { let arr = [1, 2, 3]; return 0; }")
+    check not res.hasErrors
+
+  test "slice element type mismatch":
+    let res = checkSource("func Main() -> int { let arr = [1, c8\"a\"]; return 0; }")
+    check res.hasErrors