refactor: move cli leven suggestion to options-normalizer (#5057)

Option-related processing should be done in `options-normalizer`.

- unknown flag suggestions are colored
  ![image](https://user-images.githubusercontent.com/8341033/45103027-866c7900-b161-11e8-8ee3-6467a9ca0090.png)
- unknown flags with no suggestion are now errors:
  ```
  $ bin/prettier.js --help noseminosemi
  [error] Invalid `--help` value. Expected `a flag`, but received `"noseminosemi"`.
  ```

src/cli/constant.js

@@ -156,7 +156,8 @@ const options = {
     description: dedent`
       Show CLI usage, or details about the given flag.
       Example: --help write
-    `
+    `,
+    exception: value => value === ""
   },
   "ignore-path": {
     type: "path",

src/cli/util.js

@@ -7,7 +7,6 @@ const fs = require("fs");
 const globby = require("globby");
 const chalk = require("chalk");
 const readline = require("readline");
-const leven = require("leven");
 const stringify = require("json-stable-stringify");
 
 const minimist = require("./minimist");
@@ -642,40 +641,6 @@ function flattenArray(array) {
   return [].concat.apply([], array);
 }
 
-function getOptionWithLevenSuggestion(context, options, optionName) {
-  // support aliases
-  const optionNameContainers = flattenArray(
-    options.map((option, index) => [
-      { value: option.name, index },
-      option.alias ? { value: option.alias, index } : null
-    ])
-  ).filter(Boolean);
-
-  const optionNameContainer = optionNameContainers.find(
-    optionNameContainer => optionNameContainer.value === optionName
-  );
-
-  if (optionNameContainer !== undefined) {
-    return options[optionNameContainer.index];
-  }
-
-  const suggestedOptionNameContainer = optionNameContainers.find(
-    optionNameContainer => leven(optionNameContainer.value, optionName) < 3
-  );
-
-  if (suggestedOptionNameContainer !== undefined) {
-    const suggestedOptionName = suggestedOptionNameContainer.value;
-    context.logger.warn(
-      `Unknown option name "${optionName}", did you mean "${suggestedOptionName}"?`
-    );
-
-    return options[suggestedOptionNameContainer.index];
-  }
-
-  context.logger.warn(`Unknown option name "${optionName}"`);
-  return options.find(option => option.name === "help");
-}
-
 function createChoiceUsages(choices, margin, indentation) {
   const activeChoices = choices.filter(
     choice => !choice.deprecated && choice.since !== null
@@ -692,11 +657,9 @@ function createChoiceUsages(choices, margin, indentation) {
   );
 }
 
-function createDetailedUsage(context, optionName) {
-  const option = getOptionWithLevenSuggestion(
-    context,
-    getOptionsWithOpposites(context.detailedOptions),
-    optionName
+function createDetailedUsage(context, flag) {
+  const option = getOptionsWithOpposites(context.detailedOptions).find(
+    option => option.name === flag || option.alias === flag
   );
 
   const header = createOptionUsageHeader(option);

src/main/options-normalizer.js

@@ -1,6 +1,8 @@
 "use strict";
 
 const vnopts = require("vnopts");
+const leven = require("leven");
+const chalk = require("chalk");
 
 const cliDescriptor = {
   key: key => (key.length === 1 ? `-${key}` : `--${key}`),
@@ -15,6 +17,35 @@ const cliDescriptor = {
           : `${cliDescriptor.key(key)}=${value}`
 };
 
+class FlagSchema extends vnopts.ChoiceSchema {
+  constructor({ name, flags }) {
+    super({ name, choices: flags });
+    this._flags = flags.slice().sort();
+  }
+  preprocess(value, utils) {
+    if (
+      typeof value === "string" &&
+      value.length !== 0 &&
+      this._flags.indexOf(value) === -1
+    ) {
+      const suggestion = this._flags.find(flag => leven(flag, value) < 3);
+      if (suggestion) {
+        utils.logger.warn(
+          [
+            `Unknown flag ${chalk.yellow(utils.descriptor.value(value))},`,
+            `did you mean ${chalk.blue(utils.descriptor.value(suggestion))}?`
+          ].join(" ")
+        );
+        return suggestion;
+      }
+    }
+    return value;
+  }
+  expected() {
+    return "a flag";
+  }
+}
+
 function normalizeOptions(
   options,
   optionInfos,
@@ -40,7 +71,7 @@ function optionInfosToSchemas(optionInfos, { isCLI }) {
   }
 
   for (const optionInfo of optionInfos) {
-    schemas.push(optionInfoToSchema(optionInfo, { isCLI }));
+    schemas.push(optionInfoToSchema(optionInfo, { isCLI, optionInfos }));
 
     if (optionInfo.alias && isCLI) {
       schemas.push(
@@ -55,7 +86,7 @@ function optionInfosToSchemas(optionInfos, { isCLI }) {
   return schemas;
 }
 
-function optionInfoToSchema(optionInfo, { isCLI }) {
+function optionInfoToSchema(optionInfo, { isCLI, optionInfos }) {
   let SchemaConstructor;
   const parameters = { name: optionInfo.name };
   const handlers = {};
@@ -84,6 +115,17 @@ function optionInfoToSchema(optionInfo, { isCLI }) {
       SchemaConstructor = vnopts.BooleanSchema;
       break;
     case "flag":
+      SchemaConstructor = FlagSchema;
+      parameters.flags = optionInfos
+        .map(optionInfo =>
+          [].concat(
+            optionInfo.alias || [],
+            optionInfo.description ? optionInfo.name : [],
+            optionInfo.oppositeDescription ? `no-${optionInfo.name}` : []
+          )
+        )
+        .reduce((a, b) => a.concat(b), []);
+      break;
     case "path":
       SchemaConstructor = vnopts.StringSchema;
       break;

tests_integration/__tests__/__snapshots__/early-exit.js.snap

@@ -146,21 +146,8 @@ exports[`show version with --version (stderr) 1`] = `""`;
 
 exports[`show version with --version (write) 1`] = `Array []`;
 
-exports[`show warning with --help not-found (stderr) 1`] = `
-"[warn] Unknown option name \\"not-found\\"
-"
-`;
-
-exports[`show warning with --help not-found (stdout) 1`] = `
-"-h, --help <flag>
-
-  Show CLI usage, or details about the given flag.
-  Example: --help write
-"
-`;
-
 exports[`show warning with --help not-found (typo) (stderr) 1`] = `
-"[warn] Unknown option name \\"parserr\\", did you mean \\"parser\\"?
+"[warn] Unknown flag \\"parserr\\", did you mean \\"parser\\"?
 "
 `;
 
@@ -190,8 +177,6 @@ Valid options:
 
 exports[`show warning with --help not-found (typo) (write) 1`] = `Array []`;
 
-exports[`show warning with --help not-found (write) 1`] = `Array []`;
-
 exports[`throw error and show usage with something unexpected (stderr) 1`] = `""`;
 
 exports[`throw error and show usage with something unexpected (stdout) 1`] = `
@@ -311,6 +296,15 @@ exports[`throw error with --find-config-path + multiple files (stdout) 1`] = `""
 
 exports[`throw error with --find-config-path + multiple files (write) 1`] = `Array []`;
 
+exports[`throw error with --help not-found (stderr) 1`] = `
+"[error] Invalid --help value. Expected a flag, but received \\"not-found\\".
+"
+`;
+
+exports[`throw error with --help not-found (stdout) 1`] = `""`;
+
+exports[`throw error with --help not-found (write) 1`] = `Array []`;
+
 exports[`throw error with --write + --debug-check (stderr) 1`] = `
 "[error] Cannot use --write and --debug-check together.
 "

tests_integration/__tests__/early-exit.js

@@ -44,9 +44,9 @@ describe(`show detailed usage with plugin options (manual resolution)`, () => {
   });
 });
 
-describe("show warning with --help not-found", () => {
+describe("throw error with --help not-found", () => {
   runPrettier("cli", ["--help", "not-found"]).test({
-    status: 0
+    status: 1
   });
 });