Implement parser creating AST

1 files changed, 70 insertions, 0 deletions

diff --git a/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java b/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java
new file mode 100644
index 0000000..133e9a6
--- /dev/null
+++ b/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java
@@ -0,0 +1,70 @@
+package no.eliashaugsbakk.kompilator.parsing;
+
+import static no.eliashaugsbakk.kompilator.tokenization.TokenType.KEYWORD;
+import static no.eliashaugsbakk.kompilator.tokenization.TokenType.LPAREN;
+import static no.eliashaugsbakk.kompilator.tokenization.TokenType.RPAREN;
+import static no.eliashaugsbakk.kompilator.tokenization.TokenType.SEMICOLON;
+import static no.eliashaugsbakk.kompilator.tokenization.TokenType.STRING;
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.List;
+import no.eliashaugsbakk.kompilator.parsing.node.Program;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.FunctionCall;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.StringLiteral;
+import no.eliashaugsbakk.kompilator.parsing.node.statement.ExpressionStatement;
+import no.eliashaugsbakk.kompilator.tokenization.Token;
+import org.junit.jupiter.api.Test;
+
+class ParserTest {
+
+  @Test
+  void validSyntaxBuildsCorrectTree() throws ParserException {
+    List<Token> tokens = List.of(
+        new Token(KEYWORD, "print", 1, 0),
+        new Token(LPAREN, "(", 1, 5),
+        new Token(STRING, "Hello", 1, 6),
+        new Token(RPAREN, ")", 1, 13),
+        new Token(SEMICOLON, ";", 1, 14)
+    );
+
+    AST ast = new Parser(tokens).parse();
+
+    // Verify tree structure
+    assertNotNull(ast.root);
+    assertInstanceOf(Program.class, ast.root);
+    Program program = (Program) ast.root;
+    assertEquals(1, program.statements.size());
+
+    ExpressionStatement stmt = (ExpressionStatement) program.statements.getFirst();
+    assertInstanceOf(FunctionCall.class, stmt.expression);
+
+    FunctionCall call = (FunctionCall) stmt.expression;
+    assertEquals("print", call.functionName);
+    assertEquals(1, call.arguments.size());
+    assertEquals("Hello", ((StringLiteral) call.arguments.getFirst()).value);
+  }
+
+  @Test
+  void missingSemicolonThrows() {
+    List<Token> tokens = List.of(
+        new Token(KEYWORD, "print", 1, 0),
+        new Token(LPAREN, "(", 1, 5),
+        new Token(STRING, "Hello", 1, 6),
+        new Token(RPAREN, ")", 1, 13)
+    );
+
+    assertThrows(ParserException.class, () -> new Parser(tokens).parse());
+  }
+
+  @Test
+  void missingParenthesisThrows() {
+    List<Token> tokens = List.of(
+        new Token(KEYWORD, "print", 1, 0),
+        new Token(STRING, "Hello", 1, 5),
+        new Token(RPAREN, ")", 1, 12),
+        new Token(SEMICOLON, ";", 1, 13)
+    );
+
+    assertThrows(ParserException.class, () -> new Parser(tokens).parse());
+  }
+}