Add test for verifyChannelTokenByJWT and getsAllValidChannelAccessTokenKeyIds (#785)

This change checked if we have same issue like
line/line-bot-sdk-nodejs#1569, but there is no
issue in this repository. To avoid regression about this feature, let's
add test now.

Author: Yang-33

spec/line/bot/v2/channel_access_token/api_spec.rb

@@ -0,0 +1,57 @@
+require 'spec_helper'
+
+describe 'ChannelAccessToken::ApiClient query parameter names' do
+  let(:client) { Line::Bot::V2::ChannelAccessToken::ApiClient.new }
+
+  describe 'GET /oauth2/v2.1/verify (verify_channel_token_by_jwt)' do
+    let(:access_token) { 'test_access_token_value' }
+    let(:response_body) do
+      { "clientId" => "1234567890", "expiresIn" => 12345 }.to_json
+    end
+
+    it 'sends access_token as snake_case query key, not accessToken' do
+      # Exact query match: passes only when the key is "access_token" (snake_case).
+      # If camelCase "accessToken" were used instead, the stub would not match and
+      # WebMock would raise an error, failing the test.
+      stub_request(:get, "https://api.line.me/oauth2/v2.1/verify")
+        .with(query: { "access_token" => access_token })
+        .to_return(status: 200, body: response_body, headers: { 'Content-Type' => 'application/json' })
+
+      body, status_code, _headers = client.verify_channel_token_by_jwt_with_http_info(
+        access_token: access_token
+      )
+
+      expect(status_code).to eq(200)
+      expect(body.client_id).to eq("1234567890")
+      expect(body.expires_in).to eq(12345)
+    end
+  end
+
+  describe 'GET /oauth2/v2.1/tokens/kid (gets_all_valid_channel_access_token_key_ids)' do
+    let(:client_assertion_type) { 'urn:ietf:params:oauth:client-assertion-type:jwt-bearer' }
+    let(:client_assertion) { 'test_jwt_assertion' }
+    let(:response_body) do
+      { "kids" => ["kid1", "kid2"] }.to_json
+    end
+
+    it 'sends client_assertion_type and client_assertion as snake_case query keys, not camelCase' do
+      # Exact query match: passes only when the keys are "client_assertion_type" and
+      # "client_assertion" (snake_case). If camelCase were used, the stub would not match.
+      expected_query = {
+        "client_assertion_type" => client_assertion_type,
+        "client_assertion" => client_assertion
+      }
+      stub_request(:get, "https://api.line.me/oauth2/v2.1/tokens/kid")
+        .with(query: expected_query)
+        .to_return(status: 200, body: response_body, headers: { 'Content-Type' => 'application/json' })
+
+      body, status_code, _headers = client.gets_all_valid_channel_access_token_key_ids_with_http_info(
+        client_assertion_type: client_assertion_type,
+        client_assertion: client_assertion
+      )
+
+      expect(status_code).to eq(200)
+      expect(body.kids).to eq(["kid1", "kid2"])
+    end
+  end
+end