test: add infrastructure logic unit tests (37 new tests)

Add Phase 2 test coverage for infrastructure modules:
- state.rs: 6 tests (defaults, serde round-trips, UserState deref/clone)
- provider_client.rs: 2 tests (ProviderMessage serde)
- llm.rs: 12 tests (FollowUpMessage serde, joined_len, parse_article_html
  extraction with article/main/role=main tags, fallback, exclusions,
  truncation, fragment skipping)
- chat.rs: 17 tests (doc_to_chat_session, doc_to_chat_message BSON
  conversion, resolve_provider_url for all providers)

Refactor: extract parse_article_html from fetch_article_text for testability
without HTTP. Refactor resolve_provider_url to accept explicit params
instead of full ServerState, avoiding need for MongoDB in tests.

Total test count: 129 (up from 92).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/infrastructure/chat.rs

@@ -440,7 +440,12 @@ pub async fn chat_complete(
     let session = doc_to_chat_session(&session_doc);
 
     // Resolve provider URL and model
-    let (base_url, model) = resolve_provider_url(&state, &session.provider, &session.model);
+    let (base_url, model) = resolve_provider_url(
+        &state.services.ollama_url,
+        &state.services.ollama_model,
+        &session.provider,
+        &session.model,
+    );
 
     // Parse messages from JSON
     let chat_msgs: Vec<serde_json::Value> = serde_json::from_str(&messages_json)
@@ -480,10 +485,22 @@ pub async fn chat_complete(
         .ok_or_else(|| ServerFnError::new("empty LLM response"))
 }
 
-/// Resolve the base URL for a provider, falling back to server defaults.
+/// Resolve the base URL for a provider, falling back to Ollama defaults.
+///
+/// # Arguments
+///
+/// * `ollama_url` - Default Ollama base URL from config
+/// * `ollama_model` - Default Ollama model from config
+/// * `provider` - Provider name (e.g. "openai", "anthropic", "huggingface")
+/// * `model` - Model ID (may be empty for Ollama default)
+///
+/// # Returns
+///
+/// A `(base_url, model)` tuple resolved for the given provider.
 #[cfg(feature = "server")]
-fn resolve_provider_url(
-    state: &crate::infrastructure::ServerState,
+pub(crate) fn resolve_provider_url(
+    ollama_url: &str,
+    ollama_model: &str,
     provider: &str,
     model: &str,
 ) -> (String, String) {
@@ -496,12 +513,229 @@ fn resolve_provider_url(
         ),
         // Default to Ollama
         _ => (
-            state.services.ollama_url.clone(),
+            ollama_url.to_string(),
             if model.is_empty() {
-                state.services.ollama_model.clone()
+                ollama_model.to_string()
             } else {
                 model.to_string()
             },
         ),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    // -----------------------------------------------------------------------
+    // BSON document conversion tests (server feature required)
+    // -----------------------------------------------------------------------
+
+    #[cfg(feature = "server")]
+    mod server_tests {
+        use super::super::{doc_to_chat_message, doc_to_chat_session, resolve_provider_url};
+        use crate::models::{ChatNamespace, ChatRole};
+        use mongodb::bson::{doc, oid::ObjectId, Document};
+        use pretty_assertions::assert_eq;
+
+        // -- doc_to_chat_session --
+
+        fn sample_session_doc() -> (ObjectId, Document) {
+            let oid = ObjectId::new();
+            let doc = doc! {
+                "_id": oid,
+                "user_sub": "user-42",
+                "title": "Test Session",
+                "namespace": "News",
+                "provider": "openai",
+                "model": "gpt-4",
+                "created_at": "2025-01-01T00:00:00Z",
+                "updated_at": "2025-01-02T00:00:00Z",
+                "article_url": "https://example.com/article",
+            };
+            (oid, doc)
+        }
+
+        #[test]
+        fn doc_to_chat_session_extracts_id_as_hex() {
+            let (oid, doc) = sample_session_doc();
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.id, oid.to_hex());
+        }
+
+        #[test]
+        fn doc_to_chat_session_maps_news_namespace() {
+            let (_, doc) = sample_session_doc();
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.namespace, ChatNamespace::News);
+        }
+
+        #[test]
+        fn doc_to_chat_session_defaults_to_general_for_unknown() {
+            let mut doc = sample_session_doc().1;
+            doc.insert("namespace", "SomethingElse");
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.namespace, ChatNamespace::General);
+        }
+
+        #[test]
+        fn doc_to_chat_session_extracts_all_string_fields() {
+            let (_, doc) = sample_session_doc();
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.user_sub, "user-42");
+            assert_eq!(session.title, "Test Session");
+            assert_eq!(session.provider, "openai");
+            assert_eq!(session.model, "gpt-4");
+            assert_eq!(session.created_at, "2025-01-01T00:00:00Z");
+            assert_eq!(session.updated_at, "2025-01-02T00:00:00Z");
+        }
+
+        #[test]
+        fn doc_to_chat_session_handles_missing_article_url() {
+            let oid = ObjectId::new();
+            let doc = doc! {
+                "_id": oid,
+                "user_sub": "u",
+                "title": "t",
+                "provider": "ollama",
+                "model": "m",
+                "created_at": "c",
+                "updated_at": "u",
+            };
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.article_url, None);
+        }
+
+        #[test]
+        fn doc_to_chat_session_filters_empty_article_url() {
+            let oid = ObjectId::new();
+            let doc = doc! {
+                "_id": oid,
+                "user_sub": "u",
+                "title": "t",
+                "namespace": "News",
+                "provider": "ollama",
+                "model": "m",
+                "created_at": "c",
+                "updated_at": "u",
+                "article_url": "",
+            };
+            let session = doc_to_chat_session(&doc);
+            assert_eq!(session.article_url, None);
+        }
+
+        // -- doc_to_chat_message --
+
+        fn sample_message_doc() -> (ObjectId, Document) {
+            let oid = ObjectId::new();
+            let doc = doc! {
+                "_id": oid,
+                "session_id": "sess-1",
+                "role": "Assistant",
+                "content": "Hello there!",
+                "timestamp": "2025-01-01T12:00:00Z",
+            };
+            (oid, doc)
+        }
+
+        #[test]
+        fn doc_to_chat_message_extracts_id_as_hex() {
+            let (oid, doc) = sample_message_doc();
+            let msg = doc_to_chat_message(&doc);
+            assert_eq!(msg.id, oid.to_hex());
+        }
+
+        #[test]
+        fn doc_to_chat_message_maps_assistant_role() {
+            let (_, doc) = sample_message_doc();
+            let msg = doc_to_chat_message(&doc);
+            assert_eq!(msg.role, ChatRole::Assistant);
+        }
+
+        #[test]
+        fn doc_to_chat_message_maps_system_role() {
+            let mut doc = sample_message_doc().1;
+            doc.insert("role", "System");
+            let msg = doc_to_chat_message(&doc);
+            assert_eq!(msg.role, ChatRole::System);
+        }
+
+        #[test]
+        fn doc_to_chat_message_defaults_to_user_for_unknown() {
+            let mut doc = sample_message_doc().1;
+            doc.insert("role", "SomethingElse");
+            let msg = doc_to_chat_message(&doc);
+            assert_eq!(msg.role, ChatRole::User);
+        }
+
+        #[test]
+        fn doc_to_chat_message_extracts_content_and_timestamp() {
+            let (_, doc) = sample_message_doc();
+            let msg = doc_to_chat_message(&doc);
+            assert_eq!(msg.content, "Hello there!");
+            assert_eq!(msg.timestamp, "2025-01-01T12:00:00Z");
+            assert_eq!(msg.session_id, "sess-1");
+        }
+
+        #[test]
+        fn doc_to_chat_message_attachments_always_empty() {
+            let (_, doc) = sample_message_doc();
+            let msg = doc_to_chat_message(&doc);
+            assert!(msg.attachments.is_empty());
+        }
+
+        // -- resolve_provider_url --
+
+        const TEST_OLLAMA_URL: &str = "http://localhost:11434";
+        const TEST_OLLAMA_MODEL: &str = "llama3.1:8b";
+
+        #[test]
+        fn resolve_openai_returns_api_openai() {
+            let (url, model) =
+                resolve_provider_url(TEST_OLLAMA_URL, TEST_OLLAMA_MODEL, "openai", "gpt-4o");
+            assert_eq!(url, "https://api.openai.com");
+            assert_eq!(model, "gpt-4o");
+        }
+
+        #[test]
+        fn resolve_anthropic_returns_api_anthropic() {
+            let (url, model) = resolve_provider_url(
+                TEST_OLLAMA_URL,
+                TEST_OLLAMA_MODEL,
+                "anthropic",
+                "claude-3-opus",
+            );
+            assert_eq!(url, "https://api.anthropic.com");
+            assert_eq!(model, "claude-3-opus");
+        }
+
+        #[test]
+        fn resolve_huggingface_returns_model_url() {
+            let (url, model) = resolve_provider_url(
+                TEST_OLLAMA_URL,
+                TEST_OLLAMA_MODEL,
+                "huggingface",
+                "meta-llama/Llama-2-7b",
+            );
+            assert_eq!(
+                url,
+                "https://api-inference.huggingface.co/models/meta-llama/Llama-2-7b"
+            );
+            assert_eq!(model, "meta-llama/Llama-2-7b");
+        }
+
+        #[test]
+        fn resolve_unknown_defaults_to_ollama() {
+            let (url, model) =
+                resolve_provider_url(TEST_OLLAMA_URL, TEST_OLLAMA_MODEL, "ollama", "mistral:7b");
+            assert_eq!(url, TEST_OLLAMA_URL);
+            assert_eq!(model, "mistral:7b");
+        }
+
+        #[test]
+        fn resolve_empty_model_falls_back_to_server_default() {
+            let (url, model) =
+                resolve_provider_url(TEST_OLLAMA_URL, TEST_OLLAMA_MODEL, "ollama", "");
+            assert_eq!(url, TEST_OLLAMA_URL);
+            assert_eq!(model, TEST_OLLAMA_MODEL);
+        }
+    }
+}

src/infrastructure/llm.rs

@@ -72,7 +72,25 @@ mod inner {
         }
 
         let html = resp.text().await.ok()?;
-        let document = scraper::Html::parse_document(&html);
+        parse_article_html(&html)
+    }
+
+    /// Parse article text from raw HTML without any network I/O.
+    ///
+    /// Uses a tiered extraction strategy:
+    /// 1. Try content within `<article>`, `<main>`, or `[role="main"]`
+    /// 2. Fall back to all `<p>` tags outside excluded containers
+    ///
+    /// # Arguments
+    ///
+    /// * `html` - Raw HTML string to parse
+    ///
+    /// # Returns
+    ///
+    /// The extracted text, or `None` if extraction yields < 100 chars.
+    /// Output is capped at 8000 characters.
+    pub(crate) fn parse_article_html(html: &str) -> Option<String> {
+        let document = scraper::Html::parse_document(html);
 
         // Strategy 1: Extract from semantic article containers.
         // Most news sites wrap the main content in <article>, <main>,
@@ -134,7 +152,7 @@ mod inner {
     }
 
     /// Sum the total character length of all collected text parts.
-    fn joined_len(parts: &[String]) -> usize {
+    pub(crate) fn joined_len(parts: &[String]) -> usize {
         parts.iter().map(|s| s.len()).sum()
     }
 }
@@ -325,3 +343,150 @@ pub async fn chat_followup(
         .map(|choice| choice.message.content.clone())
         .ok_or_else(|| ServerFnError::new("Empty response from Ollama"))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    // -----------------------------------------------------------------------
+    // FollowUpMessage serde tests
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn followup_message_serde_round_trip() {
+        let msg = FollowUpMessage {
+            role: "assistant".into(),
+            content: "Here is my answer.".into(),
+        };
+        let json = serde_json::to_string(&msg).expect("serialize FollowUpMessage");
+        let back: FollowUpMessage =
+            serde_json::from_str(&json).expect("deserialize FollowUpMessage");
+        assert_eq!(msg, back);
+    }
+
+    #[test]
+    fn followup_message_deserialize_from_json_literal() {
+        let json = r#"{"role":"system","content":"You are helpful."}"#;
+        let msg: FollowUpMessage = serde_json::from_str(json).expect("deserialize literal");
+        assert_eq!(msg.role, "system");
+        assert_eq!(msg.content, "You are helpful.");
+    }
+
+    // -----------------------------------------------------------------------
+    // joined_len and parse_article_html tests (server feature required)
+    // -----------------------------------------------------------------------
+
+    #[cfg(feature = "server")]
+    mod server_tests {
+        use super::super::inner::{joined_len, parse_article_html};
+        use pretty_assertions::assert_eq;
+
+        #[test]
+        fn joined_len_empty_input() {
+            assert_eq!(joined_len(&[]), 0);
+        }
+
+        #[test]
+        fn joined_len_sums_correctly() {
+            let parts = vec!["abc".into(), "de".into(), "fghij".into()];
+            assert_eq!(joined_len(&parts), 10);
+        }
+
+        // -------------------------------------------------------------------
+        // parse_article_html tests
+        // -------------------------------------------------------------------
+
+        // Helper: generate a string of given length from a repeated word.
+        fn lorem(len: usize) -> String {
+            "Lorem ipsum dolor sit amet consectetur adipiscing elit "
+                .repeat((len / 55) + 1)
+                .chars()
+                .take(len)
+                .collect()
+        }
+
+        #[test]
+        fn article_tag_extracts_text() {
+            let body = lorem(250);
+            let html = format!("<html><body><article><p>{body}</p></article></body></html>");
+            let result = parse_article_html(&html);
+            assert!(result.is_some(), "expected Some for article tag");
+            assert!(result.unwrap().contains("Lorem"));
+        }
+
+        #[test]
+        fn main_tag_extracts_text() {
+            let body = lorem(250);
+            let html = format!("<html><body><main><p>{body}</p></main></body></html>");
+            let result = parse_article_html(&html);
+            assert!(result.is_some(), "expected Some for main tag");
+        }
+
+        #[test]
+        fn fallback_to_p_tags_when_article_main_yield_little() {
+            // No <article>/<main>, so falls back to <p> tags
+            let body = lorem(250);
+            let html = format!("<html><body><div><p>{body}</p></div></body></html>");
+            let result = parse_article_html(&html);
+            assert!(result.is_some(), "expected fallback to <p> tags");
+        }
+
+        #[test]
+        fn excludes_nav_footer_aside_content() {
+            // Content only inside excluded containers -- should be excluded
+            let body = lorem(250);
+            let html = format!(
+                "<html><body>\
+                 <nav><p>{body}</p></nav>\
+                 <footer><p>{body}</p></footer>\
+                 <aside><p>{body}</p></aside>\
+                 </body></html>"
+            );
+            let result = parse_article_html(&html);
+            assert!(result.is_none(), "expected None for excluded-only content");
+        }
+
+        #[test]
+        fn returns_none_when_text_too_short() {
+            let html = "<html><body><p>Short.</p></body></html>";
+            let result = parse_article_html(html);
+            assert!(result.is_none(), "expected None for short text");
+        }
+
+        #[test]
+        fn truncates_at_8000_chars() {
+            let body = lorem(10000);
+            let html = format!("<html><body><article><p>{body}</p></article></body></html>");
+            let result = parse_article_html(&html).expect("expected Some");
+            assert!(
+                result.len() <= 8000,
+                "expected <= 8000 chars, got {}",
+                result.len()
+            );
+        }
+
+        #[test]
+        fn skips_fragments_under_30_chars() {
+            // Only fragments < 30 chars -- should yield None
+            let html = "<html><body><article>\
+                         <p>Short frag one</p>\
+                         <p>Another tiny bit</p>\
+                         </article></body></html>";
+            let result = parse_article_html(html);
+            assert!(result.is_none(), "expected None for tiny fragments");
+        }
+
+        #[test]
+        fn extracts_from_role_main_attribute() {
+            let body = lorem(250);
+            let html = format!(
+                "<html><body>\
+                 <div role=\"main\"><p>{body}</p></div>\
+                 </body></html>"
+            );
+            let result = parse_article_html(&html);
+            assert!(result.is_some(), "expected Some for role=main");
+        }
+    }
+}

src/infrastructure/provider_client.rs

@@ -146,3 +146,30 @@ pub async fn send_chat_request(
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn provider_message_serde_round_trip() {
+        let msg = ProviderMessage {
+            role: "assistant".into(),
+            content: "Hello, world!".into(),
+        };
+        let json = serde_json::to_string(&msg).expect("serialize ProviderMessage");
+        let back: ProviderMessage =
+            serde_json::from_str(&json).expect("deserialize ProviderMessage");
+        assert_eq!(msg.role, back.role);
+        assert_eq!(msg.content, back.content);
+    }
+
+    #[test]
+    fn provider_message_deserialize_from_json_literal() {
+        let json = r#"{"role":"user","content":"What is Rust?"}"#;
+        let msg: ProviderMessage = serde_json::from_str(json).expect("deserialize from literal");
+        assert_eq!(msg.role, "user");
+        assert_eq!(msg.content, "What is Rust?");
+    }
+}

src/infrastructure/state.rs

@@ -44,3 +44,91 @@ pub struct User {
     /// Avatar / profile picture URL.
     pub avatar_url: String,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn user_state_inner_default_has_empty_strings() {
+        let inner = UserStateInner::default();
+        assert_eq!(inner.sub, "");
+        assert_eq!(inner.access_token, "");
+        assert_eq!(inner.refresh_token, "");
+        assert_eq!(inner.user.email, "");
+        assert_eq!(inner.user.name, "");
+        assert_eq!(inner.user.avatar_url, "");
+    }
+
+    #[test]
+    fn user_default_has_empty_strings() {
+        let user = User::default();
+        assert_eq!(user.email, "");
+        assert_eq!(user.name, "");
+        assert_eq!(user.avatar_url, "");
+    }
+
+    #[test]
+    fn user_state_inner_serde_round_trip() {
+        let inner = UserStateInner {
+            sub: "user-123".into(),
+            access_token: "tok-abc".into(),
+            refresh_token: "ref-xyz".into(),
+            user: User {
+                email: "a@b.com".into(),
+                name: "Alice".into(),
+                avatar_url: "https://img.example.com/a.png".into(),
+            },
+        };
+        let json = serde_json::to_string(&inner).expect("serialize UserStateInner");
+        let back: UserStateInner = serde_json::from_str(&json).expect("deserialize UserStateInner");
+        assert_eq!(inner.sub, back.sub);
+        assert_eq!(inner.access_token, back.access_token);
+        assert_eq!(inner.refresh_token, back.refresh_token);
+        assert_eq!(inner.user.email, back.user.email);
+        assert_eq!(inner.user.name, back.user.name);
+        assert_eq!(inner.user.avatar_url, back.user.avatar_url);
+    }
+
+    #[test]
+    fn user_state_from_inner_and_deref() {
+        let inner = UserStateInner {
+            sub: "sub-1".into(),
+            access_token: "at".into(),
+            refresh_token: "rt".into(),
+            user: User {
+                email: "e@e.com".into(),
+                name: "Eve".into(),
+                avatar_url: "".into(),
+            },
+        };
+        let state = UserState::from(inner);
+        // Deref should give access to inner fields
+        assert_eq!(state.sub, "sub-1");
+        assert_eq!(state.user.name, "Eve");
+    }
+
+    #[test]
+    fn user_serde_round_trip() {
+        let user = User {
+            email: "bob@test.com".into(),
+            name: "Bob".into(),
+            avatar_url: "https://avatars.io/bob".into(),
+        };
+        let json = serde_json::to_string(&user).expect("serialize User");
+        let back: User = serde_json::from_str(&json).expect("deserialize User");
+        assert_eq!(user.email, back.email);
+        assert_eq!(user.name, back.name);
+        assert_eq!(user.avatar_url, back.avatar_url);
+    }
+
+    #[test]
+    fn user_state_clone_is_cheap() {
+        let inner = UserStateInner::default();
+        let state = UserState::from(inner);
+        let cloned = state.clone();
+        // Both point to the same Arc allocation
+        assert_eq!(state.sub, cloned.sub);
+    }
+}