test(yaml): add int type tests (#5868)

initial commit

yaml/parse_test.ts

@@ -351,11 +351,14 @@ Deno.test({
     assertEquals(
       parse(`
         - 0
+        - +0
+        - -0
         - 42
+        - +42
         - -42
         - 1_000
       `),
-      [0, 42, -42, 1000],
+      [0, 0, 0, 42, 42, -42, 1000],
     );
 
     // binary, octal, and hexadecimal

yaml/stringify_test.ts

@@ -87,14 +87,26 @@ Deno.test({
       stringify(42, { styles: { "!!int": "binary" } }),
       "0b101010\n",
     );
+    assertEquals(
+      stringify(-42, { styles: { "!!int": "binary" } }),
+      "-0b101010\n",
+    );
     assertEquals(
       stringify(42, { styles: { "!!int": "octal" } }),
       "052\n",
     );
+    assertEquals(
+      stringify(-42, { styles: { "!!int": "octal" } }),
+      "-052\n",
+    );
     assertEquals(
       stringify(42, { styles: { "!!int": "hexadecimal" } }),
       "0x2A\n",
     );
+    assertEquals(
+      stringify(-42, { styles: { "!!int": "hexadecimal" } }),
+      "-0x2A\n",
+    );
   },
 });