refactor: set deprecared option value warning on getter

src/cli-constant.js

@@ -168,7 +168,12 @@ const options = normalizer.normalizeDetailOptions({
   "trailing-comma": {
     type: "choice",
     isFormatOption: true,
-    choices: ["none", "es5", "all"],
+    choices: [
+      "none",
+      "es5",
+      "all",
+      { value: "", deprecated: true, redirect: "es5" }
+    ],
     description:
       "Print trailing commas wherever possible when multi-line. Defaults to none."
   },
@@ -257,7 +262,10 @@ function createOptionUsage(option) {
       // do nothing
       break;
     case "choice":
-      header += ` <${option.choices.join("|")}>`;
+      header += ` <${option.choices
+        .filter(choice => !choice.deprecated)
+        .map(choice => choice.value)
+        .join("|")}>`;
       break;
     default:
       header += ` <${option.type}>`;

src/cli-normalizer.js

@@ -3,28 +3,41 @@
 function normalizeDetailOptions(detailOptions) {
   const names = Object.keys(detailOptions).sort();
 
-  const normaliezdOptions = names.map(name =>
-    Object.assign(
-      {
-        name,
-        _getValue: (value, argv) => {
-          const option = detailOptions[name];
-          if (value && option.deprecated) {
-            let warning = `\`--${name}\` is deprecated.`;
-            if (typeof option.deprecated === "string") {
-              warning += ` ${option.deprecated}`;
-            }
-            console.warn(warning);
+  const normaliezdOptions = names.map(name => {
+    const option = detailOptions[name];
+    return Object.assign({}, option, {
+      name,
+      choices:
+        option.choices &&
+        option.choices.map(
+          choice => (typeof choice === "string" ? { value: choice } : choice)
+        ),
+      _getValue: (value, argv) => {
+        if (value && option.deprecated) {
+          let warning = `\`--${name}\` is deprecated.`;
+          if (typeof option.deprecated === "string") {
+            warning += ` ${option.deprecated}`;
           }
-          if (typeof option.getter === "function") {
-            return option.getter(value, argv);
-          }
-          return value;
+          console.warn(warning);
         }
-      },
-      detailOptions[name]
-    )
-  );
+        if (typeof option.getter === "function") {
+          return option.getter(value, argv);
+        }
+        if (option.type === "choice") {
+          const choice = option.choices.find(choice => choice.value === value);
+          if (choice !== undefined && choice.deprecated) {
+            const warningValue =
+              value === "" ? "without an argument" : `with value \`${value}\``;
+            console.warn(
+              `\`--${name}\` ${warningValue} is deprecated. Automatically redirect to \`--${name}=${choice.redirect}\`.`
+            );
+            return choice.redirect;
+          }
+        }
+        return value;
+      }
+    });
+  });
 
   normaliezdOptions.forEach(normalizedOption => {
     normaliezdOptions[normalizedOption.name] = normalizedOption;

src/cli-util.js

@@ -50,15 +50,6 @@ function getIntOption(argv, optionName) {
 function getTrailingComma(argv) {
   const value = argv["trailing-comma"];
 
-  /* istanbul ignore if */
-  if (value === "") {
-    console.warn(
-      "Warning: `--trailing-comma` was used without an argument. This is deprecated. " +
-        'Specify "none", "es5", or "all".'
-    );
-    return "es5";
-  }
-
   validator.validateChoiceOption(value, constant.options["trailing-comma"], {
     exceptions: [undefined]
   });

src/cli-validator.js

@@ -25,14 +25,16 @@ function validateIntOption(value, option, opts) {
 }
 
 function validateChoiceOption(value, option) {
-  if (option.choices.indexOf(value) === -1) {
+  if (!option.choices.some(choice => choice.value === value)) {
     throw new Error(
       `Invalid option for --${option.name}.\nExpected ${getJoinedChoices()}, but received: "${value}"`
     );
   }
 
   function getJoinedChoices() {
-    const choices = option.choices.map(choice => `"${choice}"`);
+    const choices = option.choices
+      .filter(choice => !choice.deprecated)
+      .map(choice => `"${choice.value}"`);
     const head = choices.slice(0, -2);
     const tail = choices.slice(-2);
     return head.concat(tail.join(" or ")).join(", ");

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

@@ -13,7 +13,7 @@ exports[`deprecated option values are warned 1`] = `
 `;
 
 exports[`deprecated option values are warned 2`] = `
-"Warning: \`--trailing-comma\` was used without an argument. This is deprecated. Specify \\"none\\", \\"es5\\", or \\"all\\".
+"\`--trailing-comma\` without an argument is deprecated. Automatically redirect to \`--trailing-comma=es5\`.
 "
 `;