Add version command (#4)

main.c

@@ -1,6 +1,7 @@
 #include <sourcekitd/sourcekitd.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 char *copy_file_contents(char *path);
@@ -98,10 +99,15 @@ int perform_sourcekit_request_from_yamlfile(char *filepath) {
 
 int main(int argc, char **argv) {
   if (argc != 2) {
-    fprintf(stderr, "Usage: skit YAMLFILE\n");
+    fprintf(stderr, "Usage: skit [YAMLFILE|-v|--version]\n");
     return 1;
   }
 
+  if (strcmp(argv[1], "-v") == 0 || strcmp(argv[1], "--version") == 0) {
+    printf("0.1.2\n");
+    return 0;
+  }
+
   char *filepath = argv[1];
   if (!file_readable(filepath)) {
     fprintf(stderr, "No readable file exists at '%s'\n", filepath);

tests/test_executable.py

@@ -48,4 +48,22 @@ def test_no_argument(self):
         code, out, err = run_command(None)
         self.assertEqual(code, 1)
         self.assertEqual(out, "")
-        self.assertEqual(err, "Usage: skit YAMLFILE\n")
+        self.assertEqual(err, "Usage: skit [YAMLFILE|-v|--version]\n")
+
+    def test_invalid_flag(self):
+        code, out, err = run_command("--versionfoobar")
+        self.assertEqual(code, 1)
+        self.assertEqual(out, "")
+        self.assertEqual(err, "No readable file exists at '--versionfoobar'\n")
+
+    def test_version_command(self):
+        code, out, err = run_command("--version")
+        self.assertEqual(code, 0)
+        self.assertRegexpMatches(out, r"\d+\.\d+\.\d+")
+        self.assertEqual(err, "")
+
+    def test_short_version_command(self):
+        code, out, err = run_command("-v")
+        self.assertEqual(code, 0)
+        self.assertRegexpMatches(out, r"\d+\.\d+\.\d+")
+        self.assertEqual(err, "")