[Fix] no-unused-modules: improve schema

 - allow empty arrays in `src` and `ignoreExports`
 - enforce uniqueness in `src` and `ignoreExport` lists
 - allow false/true combo on missingExports/unusedExports

Author: ljharb

CHANGELOG.md

@@ -15,6 +15,7 @@ This change log adheres to standards from [Keep a CHANGELOG](https://keepachange
 - [`order`]: partial fix for [#2687] (thanks [@ljharb])
 - [`no-duplicates`]: Detect across type and regular imports ([#2835], thanks [@benkrejci])
 - [`extensions`]: handle `.` and `..` properly ([#2778], thanks [@benasher44])
+ - [`no-unused-modules`]: improve schema (thanks [@ljharb])
 
 ### Changed
 - [Docs] [`no-duplicates`]: fix example schema ([#2684], thanks [@simmo])

docs/rules/no-unused-modules.md

@@ -12,7 +12,7 @@ Reports:
 
 ### Usage
 
-In order for this plugin to work, one of the options `missingExports` or `unusedExports` must be enabled (see "Options" section below). In the future, these options will be enabled by default (see https://github.com/import-js/eslint-plugin-import/issues/1324)
+In order for this plugin to work, at least one of the options `missingExports` or `unusedExports` must be enabled (see "Options" section below). In the future, these options will be enabled by default (see https://github.com/import-js/eslint-plugin-import/issues/1324)
 
 Example:
 ```

src/rules/no-unused-modules.js

@@ -416,17 +416,16 @@ module.exports = {
         src: {
           description: 'files/paths to be analyzed (only for unused exports)',
           type: 'array',
-          minItems: 1,
+          uniqueItems: true,
           items: {
             type: 'string',
             minLength: 1,
           },
         },
         ignoreExports: {
-          description:
-            'files/paths for which unused exports will not be reported (e.g module entry points)',
+          description: 'files/paths for which unused exports will not be reported (e.g module entry points)',
           type: 'array',
-          minItems: 1,
+          uniqueItems: true,
           items: {
             type: 'string',
             minLength: 1,
@@ -441,37 +440,23 @@ module.exports = {
           type: 'boolean',
         },
       },
-      not: {
-        properties: {
-          unusedExports: { enum: [false] },
-          missingExports: { enum: [false] },
-        },
-      },
-      anyOf: [{
-        not: {
+      anyOf: [
+        {
           properties: {
             unusedExports: { enum: [true] },
+            src: {
+              minItems: 1,
+            },
           },
+          required: ['unusedExports'],
         },
-        required: ['missingExports'],
-      }, {
-        not: {
+        {
           properties: {
             missingExports: { enum: [true] },
           },
+          required: ['missingExports'],
         },
-        required: ['unusedExports'],
-      }, {
-        properties: {
-          unusedExports: { enum: [true] },
-        },
-        required: ['unusedExports'],
-      }, {
-        properties: {
-          missingExports: { enum: [true] },
-        },
-        required: ['missingExports'],
-      }],
+      ],
     }],
   },