Add more sema checks

crates/pine/src/lib.rs

@@ -254,10 +254,13 @@ impl<O: PineOutput> ScriptBuilder<O> {
             builtins.insert(name.clone(), value.clone());
         }
 
-        // Semantic pre-check: reject invalid programs before execution.
-        let diagnostics = pine_sema::analyze(&program, &builtins);
-        if !diagnostics.is_empty() {
-            return Err(Error::Sema(diagnostics));
+        // Semantic pre-check: reject if sema produces errors
+        let errors: Vec<_> = pine_sema::analyze(&program, &builtins)
+            .into_iter()
+            .filter(|diagnostic| diagnostic.severity == pine_diagnostics::Severity::Error)
+            .collect();
+        if !errors.is_empty() {
+            return Err(Error::Sema(errors));
         }
 
         // Create interpreter and load builtin namespace objects

tests/testdata/errors/duplicate_parameter.pine

@@ -0,0 +1,8 @@
+//@version=5
+indicator("errors/duplicate_parameter")
+// A parameter name may appear only once.
+
+f(x, x) => x
+
+// Expected error:
+// error [duplicate-parameter]: parameter `x` is declared more than once

tests/testdata/errors/not_callable.pine

@@ -0,0 +1,9 @@
+//@version=5
+indicator("errors/not_callable")
+// A value cannot be called like a function.
+
+x = 5
+y = x()
+
+// Expected error:
+// error [not-callable] 6:6: `x` is a variable, not a function

tests/testdata/errors/recursion.pine

@@ -0,0 +1,8 @@
+//@version=5
+indicator("errors/recursion")
+// Pine does not allow a function to call itself.
+
+f(x) => f(x - 1)
+
+// Expected error:
+// error [recursion] 5:10: `f` calls itself; Pine does not allow recursion

tests/testdata/errors/recursion_through_helper.pine

@@ -0,0 +1,10 @@
+//@version=5
+indicator("errors/recursion_through_helper")
+// Recursion is found even when the self-call is nested inside another call; the
+// non-recursive helper is not flagged.
+
+double(x) => x * 2
+f(x) => double(f(x))
+
+// Expected error:
+// error [recursion] 7:17: `f` calls itself; Pine does not allow recursion

tests/testdata/errors/unknown_type.pine

@@ -0,0 +1,8 @@
+//@version=5
+indicator("errors/unknown_type")
+// A type annotation must name a built-in or a declared type.
+
+UnknownType x = na
+
+// Expected error:
+// error [unknown-type]: unknown type `UnknownType`

tests/testdata/errors/user_function_too_few_args.pine

@@ -0,0 +1,9 @@
+//@version=5
+indicator("errors/user_function_too_few_args")
+// A user function requires all of its non-defaulted parameters.
+
+f(a, b) => a + b
+x = f(1)
+
+// Expected error:
+// error [too-few-arguments] 6:6: `f` requires at least 2 arguments, found 1

tests/testdata/errors/user_function_too_many_args.pine

@@ -0,0 +1,9 @@
+//@version=5
+indicator("errors/user_function_too_many_args")
+// A user function rejects more arguments than it declares.
+
+f(a) => a
+x = f(1, 2)
+
+// Expected error:
+// error [too-many-arguments] 6:6: `f` takes at most 1 arguments, found 2