🐛 Guard expires_latency when a token has no known expiry

CHANGELOG.md

@@ -28,6 +28,8 @@ Please file a bug if you notice a violation of semantic versioning.
 
 ### Fixed
 
+- `OAuth2::AccessToken` no longer raises `NoMethodError` when `expires_latency` is set but the token has no known expiry (no `expires_in`/`expires_at`, or `expires_in: 0`), e.g. `client.get_token(params, expires_latency: 30)` against a provider that omits `expires_in` by @iamibi
+
 ### Security
 
 ## [2.0.25] - 2026-07-14

lib/oauth2/access_token.rb

@@ -171,7 +171,7 @@ def initialize(client, token, opts = {})
       @expires_at &&= convert_expires_at(@expires_at)
       @expires_latency &&= @expires_latency.to_i
       @expires_at ||= Time.now.to_i + @expires_in if @expires_in && !@expires_in.zero?
-      @expires_at -= @expires_latency if @expires_latency
+      @expires_at -= @expires_latency if @expires_at && @expires_latency
       @options = {
         mode: opts.delete(:mode) || :header,
         header_format: opts.delete(:header_format) || "Bearer %s",

spec/oauth2/access_token_spec.rb

@@ -795,6 +795,56 @@ def assert_initialized_token(target)
         target = described_class.from_hash(client, hash.merge(expires_at: expires_at))
         expect(target.expires_at).to eq(expires_at - expires_latency)
       end
+
+      context "when neither expires_in nor expires_at is provided" do
+        let(:hash) do
+          {
+            access_token: token,
+            expires_latency: expires_latency,
+          }
+        end
+
+        it "does not raise" do
+          expect { described_class.from_hash(client, hash) }.not_to raise_error
+        end
+
+        it "does not expire" do
+          target = described_class.from_hash(client, hash)
+          expect(target.expires_at).to be_nil
+          expect(target).not_to be_expires
+          expect(target).not_to be_expired
+        end
+
+        it "retains expires_latency" do
+          target = described_class.from_hash(client, hash)
+          expect(target.expires_latency).to eq(expires_latency)
+        end
+      end
+
+      context "when expires_in is zero" do
+        let(:expires_in) { 0 }
+
+        it "does not raise" do
+          expect { described_class.from_hash(client, hash) }.not_to raise_error
+        end
+
+        it "does not expire" do
+          target = described_class.from_hash(client, hash)
+          expect(target.expires_at).to be_nil
+          expect(target).not_to be_expires
+        end
+      end
+
+      context "when the token endpoint response omits expires_in" do
+        let(:refresh_body) { JSON.dump(access_token: "refreshed_foo", refresh_token: "refresh_bar") }
+
+        it "builds a non-expiring token via Client#get_token" do
+          target = client.get_token({grant_type: "refresh_token", refresh_token: "abaca"}, {expires_latency: expires_latency})
+          expect(target.token).to eq("refreshed_foo")
+          expect(target.expires_latency).to eq(expires_latency)
+          expect(target).not_to be_expires
+        end
+      end
     end
   end