tests: unit: add parsing tests

tests/unit/common.c

@@ -0,0 +1,15 @@
+#include <criterion/redirect.h>
+
+void redirect_streams(void)
+{
+    cr_redirect_stdin();
+    cr_redirect_stdout();
+    cr_redirect_stderr();
+}
+
+void write_to_stdin(const char *input)
+{
+    FILE *f = cr_get_redirected_stdin();
+    fputs(input, f);
+    fclose(f); // Make sure to send EOF when parsing
+}

tests/unit/common.h

@@ -0,0 +1,7 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+void redirect_streams(void);
+void write_to_stdin(const char *input);
+
+#endif /* !COMMON_H */

tests/unit/parse.c

@@ -0,0 +1,116 @@
+#include <criterion/criterion.h>
+#include <criterion/redirect.h>
+
+#include "common.h"
+
+#include "ast/ast.h"
+#include "parse/parse-jitters.h"
+
+TestSuite(parser, .init = redirect_streams);
+
+void do_correct(const char *input)
+{
+    write_to_stdin(input);
+    struct ast_node *ast = NULL;
+
+    cr_assert_eq(yyparse(&ast), 0);
+    cr_assert_not_null(ast);
+
+    destroy_ast(ast);
+}
+
+void do_incorrect(const char *input)
+{
+    write_to_stdin(input);
+    struct ast_node *ast = NULL;
+
+    cr_expect_neq(yyparse(&ast), 0);
+    cr_expect_null(ast);
+
+    destroy_ast(ast);
+}
+
+Test(parser, empty)
+{
+    do_incorrect("");
+}
+
+Test(parser, trailing_operator)
+{
+    do_incorrect("1 +");
+}
+
+Test(parser, trailing_expression)
+{
+    do_incorrect("1 1");
+}
+
+Test(parser, double_operator)
+{
+    do_incorrect("1 * * 1");
+}
+
+Test(parser, one)
+{
+    do_correct("1");
+}
+
+Test(parser, the_answer)
+{
+    do_correct("42");
+}
+
+Test(parser, int_max)
+{
+    do_correct("2147483647");
+}
+
+Test(parser, whitespace)
+{
+    do_correct("   1   ");
+}
+
+Test(parser, more_whitespace)
+{
+    do_correct("   1   + 2     ");
+}
+
+Test(parser, one_plus_one)
+{
+    do_correct("1+1");
+}
+
+Test(parser, one_minus_one)
+{
+    do_correct("1-1");
+}
+
+Test(parser, additions)
+{
+    do_correct("1+1+1+1+1");
+}
+
+Test(parser, substractions)
+{
+    do_correct("1-1-1-1-1");
+}
+
+Test(parser, multiplication)
+{
+    do_correct("2 * 3");
+}
+
+Test(parser, multiplications)
+{
+    do_correct("1 * 2 * 3 * 4");
+}
+
+Test(parser, division)
+{
+    do_correct("12 / 3");
+}
+
+Test(parser, divisions)
+{
+    do_correct("24 / 4 / 3 / 2");
+}