added parsing for function literals

2025-07-15 00:56:12 +02:00
parent 85f530f5f9
commit 0b2a12cef7
4 changed files with 228 additions and 0 deletions
--- a/test/parser/function.cpp
+++ b/test/parser/function.cpp
@@ -0,0 +1,134 @@
+#include "ast/expressions/function.hpp"
+
+#include "ast/statements/return.hpp"
+#include "utils.hpp"
+
+#include <doctest.h>
+
+TEST_SUITE("Parser: function") {
+    TEST_CASE("Malformed if then else (checking for memory leaks)") {}
+
+    TEST_CASE_FIXTURE(ParserFixture, "Parse well formed function literal") {
+        SUBCASE("no param function") {
+            setup("\
+fn () {\
+    return true;\
+}\
+");
+            REQUIRE(program->statements.size() == 1);
+            CHECK(program->statements[0]->token_literal() == "fn");
+
+            ast::expression_stmt* expr_stmt =
+                cast<ast::expression_stmt>(program->statements[0]);
+
+            ast::function_literal* fun =
+                cast<ast::function_literal>(expr_stmt->expression);
+
+            // parameters
+            CHECK(fun->parameters.size() == 0);
+
+            // block
+            REQUIRE(fun->block->statements.size() == 1);
+            ast::return_stmt* ret =
+                cast<ast::return_stmt>(fun->block->statements[0]);
+            test_boolean_literal(ret->value, true);
+
+            // full string
+            CHECK(fun->str() == "fn (){return true;}");
+        }
+
+        SUBCASE("one param function") {
+            setup("\
+fn (x) {\
+    return x + 1;\
+}\
+");
+            REQUIRE(program->statements.size() == 1);
+            CHECK(program->statements[0]->token_literal() == "fn");
+
+            ast::expression_stmt* expr_stmt =
+                cast<ast::expression_stmt>(program->statements[0]);
+
+            ast::function_literal* fun =
+                cast<ast::function_literal>(expr_stmt->expression);
+
+            // parameters
+            REQUIRE(fun->parameters.size() == 1);
+            test_identifier(fun->parameters[0], "x");
+
+            // block
+            REQUIRE(fun->block->statements.size() == 1);
+            ast::return_stmt* ret =
+                cast<ast::return_stmt>(fun->block->statements[0]);
+            test_infix_expression(ret->value, "x", "+", 1);
+
+            // full string
+            CHECK(fun->str() == "fn (x){return (x + 1);}");
+        }
+
+        SUBCASE("two param function") {
+            setup("\
+fn (x, y) {\
+    return x + y;\
+}\
+");
+            REQUIRE(program->statements.size() == 1);
+            CHECK(program->statements[0]->token_literal() == "fn");
+
+            ast::expression_stmt* expr_stmt =
+                cast<ast::expression_stmt>(program->statements[0]);
+
+            ast::function_literal* fun =
+                cast<ast::function_literal>(expr_stmt->expression);
+
+            // parameters
+            REQUIRE(fun->parameters.size() == 2);
+            test_identifier(fun->parameters[0], "x");
+            test_identifier(fun->parameters[1], "y");
+
+            // block
+            REQUIRE(fun->block->statements.size() == 1);
+            ast::return_stmt* ret =
+                cast<ast::return_stmt>(fun->block->statements[0]);
+            test_infix_expression(ret->value, "x", "+", "y");
+
+            // full string
+            CHECK(fun->str() == "fn (x, y){return (x + y);}");
+        }
+
+        SUBCASE("two param function assigned to variable") {
+            setup("\
+let fun = fn (x, y) {\
+    return x + y;\
+}\
+");
+            REQUIRE(program->statements.size() == 1);
+            CHECK(program->statements[0]->token_literal() == "let");
+
+            ast::let_stmt* let_stmt =
+                cast<ast::let_stmt>(program->statements[0]);
+
+            // let lhs
+            test_identifier(let_stmt->name, "fun");
+
+            // let rhs
+            CHECK(let_stmt->value->token_literal() == "fn");
+            ast::function_literal* fun =
+                cast<ast::function_literal>(let_stmt->value);
+
+            // parameters
+            REQUIRE(fun->parameters.size() == 2);
+            test_identifier(fun->parameters[0], "x");
+            test_identifier(fun->parameters[1], "y");
+
+            // block
+            REQUIRE(fun->block->statements.size() == 1);
+            ast::return_stmt* ret =
+                cast<ast::return_stmt>(fun->block->statements[0]);
+            test_infix_expression(ret->value, "x", "+", "y");
+
+            // full string
+            CHECK(fun->str() == "fn (x, y){return (x + y);}");
+        }
+    }
+}