tests: unit: add parsing tests

tests/local.am

@@ -3,3 +3,40 @@ TEST_LOG_DRIVER = \
     env AM_TAP_AWK='$(AWK)' $(SHELL) $(top_srcdir)/build-aux/tap-driver.sh
 
 TESTS =
+
+# Distribute the leak suppression file
+EXTRA_DIST += %D%/unit/leak.suppr
+
+if USING_CRITERION
+# Add our testsuite to `make check` only if Criterion is detected
+check_PROGRAMS = testsuite
+
+# Add our testsuite to the TAP driver
+TESTS += $(check_PROGRAMS)
+
+# Setup Criterion TAP output, and suppress leak from Criterion
+AM_TESTS_ENVIRONMENT = \
+    CRITERION_OUTPUTS='tap:-'; \
+    export CRITERION_OUTPUTS; \
+    LSAN_OPTIONS=suppressions=%D%/unit/leak.suppr; \
+    export LSAN_OPTIONS; \
+    $(NULL)
+
+# Unit-test sources
+testsuite_SOURCES = \
+    %D%/unit/common.c \
+    %D%/unit/common.h \
+    %D%/unit/parse.c \
+    $(NULL)
+
+# Libraries being tested
+testsuite_LDADD = \
+    libast.a \
+    libparse.a \
+    $(NULL)
+
+# Needed flags
+testsuite_CFLAGS = $(AM_CFLAGS) $(CRITERION_CFLAGS)
+testsuite_CPPFLAGS = $(AM_CPPFLAGS)
+testsuite_LDFLAGS = $(AM_LDFLAGS) $(CRITERION_LIBS)
+endif

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");
+}