feat: adds strictOptions() (#1738)

docs/api.md

@@ -1518,6 +1518,13 @@ Similar to `.strict()`, except that it only applies to unrecognized commands. A
 user can still provide arbitrary options, but unknown positional commands
 will raise an error.
 
+.strictOptions([enabled=true])
+---------
+
+Similar to `.strict()`, except that it only applies to unrecognized options. A
+user can still provide arbitrary positional commands, but unknown options
+will raise an error.
+
 <a name="string"></a>.string(key)
 ------------
 

lib/validation.ts

@@ -114,7 +114,7 @@ export function validation (yargs: YargsInstance, usage: UsageInstance, y18n: Y1
   }
 
   // check for unknown arguments (strict-mode).
-  self.unknownArguments = function unknownArguments (argv, aliases, positionalMap, isDefaultCommand) {
+  self.unknownArguments = function unknownArguments (argv, aliases, positionalMap, isDefaultCommand, checkPositionals = true) {
     const commandKeys = yargs.getCommandInstance().getCommands()
     const unknown: string[] = []
     const currentContext = yargs.getContext()
@@ -129,7 +129,7 @@ export function validation (yargs: YargsInstance, usage: UsageInstance, y18n: Y1
       }
     })
 
-    if ((currentContext.commands.length > 0) || (commandKeys.length > 0) || isDefaultCommand) {
+    if (checkPositionals && ((currentContext.commands.length > 0) || (commandKeys.length > 0) || isDefaultCommand)) {
       argv._.slice(currentContext.commands.length).forEach((key) => {
         if (commandKeys.indexOf(key) === -1) {
           unknown.push(key)
@@ -428,7 +428,8 @@ export interface ValidationInstance {
     argv: Arguments,
     aliases: DetailedArguments['aliases'],
     positionalMap: Dictionary,
-    isDefaultCommand: boolean
+    isDefaultCommand: boolean,
+    checkPositionals?: boolean,
   ): void
   unknownCommands(argv: Arguments): boolean
 }

lib/yargs.ts

@@ -170,6 +170,7 @@ export function Yargs (processArgs: string | string[] = [], cwd = process.cwd(),
       groups,
       strict,
       strictCommands,
+      strictOptions,
       completionCommand,
       output,
       exitError,
@@ -198,6 +199,7 @@ export function Yargs (processArgs: string | string[] = [], cwd = process.cwd(),
       parsed: self.parsed,
       strict,
       strictCommands,
+      strictOptions,
       completionCommand,
       parseFn,
       parseContext,
@@ -942,6 +944,14 @@ export function Yargs (processArgs: string | string[] = [], cwd = process.cwd(),
   }
   self.getStrictCommands = () => strictCommands
 
+  let strictOptions = false
+  self.strictOptions = function (enabled) {
+    argsert('[boolean]', [enabled], arguments.length)
+    strictOptions = enabled !== false
+    return self
+  }
+  self.getStrictOptions = () => strictOptions
+
   let parserConfig: Configuration = {}
   self.parserConfiguration = function parserConfiguration (config) {
     argsert('<object>', [config], arguments.length)
@@ -1371,6 +1381,8 @@ export function Yargs (processArgs: string | string[] = [], cwd = process.cwd(),
     }
     if (strict && !failedStrictCommands) {
       validation.unknownArguments(argv, aliases, positionalMap, isDefaultCommand)
+    } else if (strictOptions) {
+      validation.unknownArguments(argv, aliases, {}, false, false)
     }
     validation.customChecks(argv, aliases)
     validation.limitedChoices(argv)
@@ -1514,6 +1526,7 @@ export interface YargsInstance {
   getParserConfiguration (): Configuration
   getStrict (): boolean
   getStrictCommands (): boolean
+  getStrictOptions (): boolean
   getUsageInstance (): UsageInstance
   getValidationInstance (): ValidationInstance
   global (keys: string | string[], global?: boolean): YargsInstance
@@ -1567,6 +1580,7 @@ export interface YargsInstance {
   skipValidation (keys: string | string[]): YargsInstance
   strict (enable?: boolean): YargsInstance
   strictCommands (enable?: boolean): YargsInstance
+  strictOptions (enable?: boolean): YargsInstance
   string (key: string | string []): YargsInstance
   terminalWidth (): number | null
   updateStrings (obj: Dictionary<string>): YargsInstance
@@ -1697,6 +1711,7 @@ interface FrozenYargsInstance {
   groups: Dictionary<string[]>
   strict: boolean
   strictCommands: boolean
+  strictOptions: boolean
   completionCommand: string | null
   output: string
   exitError: YError | string | undefined | null