test: add test for deprecated option value

tests_integration/__tests__/__snapshots__/arg-parsing.js.snap

@@ -7,6 +7,16 @@ exports[`boolean flags do not swallow the next argument 1`] = `
 
 exports[`boolean flags do not swallow the next argument 2`] = `""`;
 
+exports[`deprecated option values are warned 1`] = `
+"console.log(\\"could be single quote and without semi\\");
+"
+`;
+
+exports[`deprecated option values are warned 2`] = `
+"Warning: \`--trailing-comma\` was used without an argument. This is deprecated. Specify \\"none\\", \\"es5\\", or \\"all\\".
+"
+`;
+
 exports[`deprecated options are warned 1`] = `
 "console.log(\\"could be single quote and without semi\\");
 "

tests_integration/__tests__/arg-parsing.js

@@ -41,3 +41,14 @@ test("deprecated options are warned", () => {
   expect(result.stderr).toMatchSnapshot();
   expect(result.status).toEqual(0);
 });
+
+test("deprecated option values are warned", () => {
+  const result = runPrettier("cli/arg-parsing", [
+    "file.js",
+    "--trailing-comma"
+  ]);
+
+  expect(result.stdout).toMatchSnapshot();
+  expect(result.stderr).toMatchSnapshot();
+  expect(result.status).toEqual(0);
+});