fix: only add mutually exclusive description if there are multiple arguments in a lookup argument set

examples/core_api/argument_sets/single_lookup.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module CoreAPI
+  module ArgumentSets
+    class SingleLookup < Apia::LookupArgumentSet
+
+      name "Single Lookup"
+      description "Provides for something to be looked up"
+
+      argument :id, type: :string
+
+    end
+  end
+end

examples/core_api/endpoints/test_endpoint.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "core_api/argument_sets/object_lookup"
+require "core_api/argument_sets/single_lookup"
 
 module CoreAPI
   module Endpoints
@@ -10,6 +11,7 @@ class TestEndpoint < Apia::Endpoint
       description "Returns the current time"
 
       argument :object, type: ArgumentSets::ObjectLookup, required: true
+      argument :thing, type: ArgumentSets::SingleLookup, required: true
       argument :scalar, type: :string, required: true do
         description "Any string will do, it's not validated"
       end

lib/apia/open_api/objects/parameters.rb

@@ -146,7 +146,8 @@ def add_description_section(description, addition)
         end
 
         def add_lookup_description(description)
-          return unless @argument.type.klass.ancestors.include?(Apia::LookupArgumentSet)
+          return unless @argument.type.klass.ancestors.include?(Apia::LookupArgumentSet) &&
+                        @argument.type.klass.definition.arguments.length > 1
 
           add_description_section(
             description,

lib/apia/open_api/objects/schema.rb

@@ -80,7 +80,9 @@ def generate_child_schemas
             @children = @definition.fields.values
           elsif @definition.type.argument_set?
             @children = @definition.type.klass.definition.arguments.values
-            if @definition.type.klass.ancestors.include?(Apia::LookupArgumentSet)
+            if @definition.type.klass.ancestors.include?(Apia::LookupArgumentSet) &&
+               @definition.type.klass.definition.arguments.length > 1
+
               @schema[:description] ||=
                 "All '#{@definition.name}[]' params are mutually exclusive, only one can be provided."
             end

spec/support/fixtures/openapi.json

@@ -841,6 +841,14 @@
             },
             "description": "The permalink of the object to look up. \n\n All 'object[]' params are mutually exclusive, only one can be provided."
           },
+          {
+            "in": "query",
+            "name": "thing[id]",
+            "schema": {
+              "type": "string"
+            },
+            "description": ""
+          },
           {
             "name": "scalar",
             "in": "query",
@@ -916,13 +924,17 @@
                   "object": {
                     "$ref": "#/components/schemas/ObjectLookup"
                   },
+                  "thing": {
+                    "$ref": "#/components/schemas/SingleLookup"
+                  },
                   "scalar": {
                     "type": "string",
                     "description": "Any string will do, it's not validated"
                   }
                 },
                 "required": [
                   "object",
+                  "thing",
                   "scalar"
                 ]
               }
@@ -1483,6 +1495,14 @@
           "object_not_found"
         ]
       },
+      "SingleLookup": {
+        "type": "object",
+        "properties": {
+          "id": {
+            "type": "string"
+          }
+        }
+      },
       "PostTestObject200ResponseTime": {
         "type": "object",
         "properties": {