fix: create test dir if not exists

lox_tests/var.lox

@@ -0,0 +1 @@
+var a = 1;

lox_tests/var/bytecode

@@ -0,0 +1,3 @@
+Chunk {
+    code: [],
+}

lox_tests/var/syntax

@@ -0,0 +1,12 @@
+Diagnostic {
+    severity: Error,
+    span: @0..@3,
+    message: "extra tokens after statement",
+    labels: [
+        Label {
+            span: @0..@3,
+            message: "here",
+        },
+    ],
+    children: [],
+}

lox_tests/var/token

@@ -0,0 +1,13 @@
+TokenTree {
+    source text: "var a = 1;",
+    tokens: [
+        Alphabetic(var),
+        Whitespace(' '),
+        Alphabetic(a),
+        Whitespace(' '),
+        Op(=),
+        Whitespace(' '),
+        Number(1),
+        Semicolon,
+    ],
+}

src/main.rs

@@ -49,6 +49,10 @@ impl TestCase {
         // `foo/bar/{token,syntax,bytecode,execute}`
         let parent = lox.parent().unwrap();
         let lox_dir = parent.join(lox.file_stem().unwrap());
+        if !lox_dir.exists() {
+            fs::create_dir(&lox_dir).unwrap();
+        }
+
         let token = lox_dir.join("token");
         let syntax = lox_dir.join("syntax");
         let bytecode = lox_dir.join("bytecode");