agent: Ensure that web search tool is always available (#29799)

Some changes in the LanguageModelRegistry caused the web search tool not
to show up, because the `DefaultModelChanged` event is not emitted at
startup anymore.

Release Notes:

- agent: Fixed an issue where the web search tool would not be available
after starting Zed (only when using zed.dev as a provider).

crates/assistant_tools/src/assistant_tools.rs

@@ -34,7 +34,7 @@ use assistant_settings::AssistantSettings;
 use assistant_tool::ToolRegistry;
 use copy_path_tool::CopyPathTool;
 use feature_flags::{AgentStreamEditsFeatureFlag, FeatureFlagAppExt};
-use gpui::App;
+use gpui::{App, Entity};
 use http_client::HttpClientWithUrl;
 use language_model::LanguageModelRegistry;
 use move_path_tool::MovePathTool;
@@ -101,19 +101,12 @@ pub fn init(http_client: Arc<HttpClientWithUrl>, cx: &mut App) {
     cx.observe_global::<SettingsStore>(register_edit_file_tool)
         .detach();
 
+    register_web_search_tool(&LanguageModelRegistry::global(cx), cx);
     cx.subscribe(
         &LanguageModelRegistry::global(cx),
         move |registry, event, cx| match event {
             language_model::Event::DefaultModelChanged => {
-                let using_zed_provider = registry
+                register_web_search_tool(&registry, cx);
-                    .read(cx)
-                    .default_model()
-                    .map_or(false, |default| default.is_provided_by_zed());
-                if using_zed_provider {
-                    ToolRegistry::global(cx).register_tool(WebSearchTool);
-                } else {
-                    ToolRegistry::global(cx).unregister_tool(WebSearchTool);
-                }
             }
             _ => {}
         },
@@ -121,6 +114,18 @@ pub fn init(http_client: Arc<HttpClientWithUrl>, cx: &mut App) {
     .detach();
 }
 
+fn register_web_search_tool(registry: &Entity<LanguageModelRegistry>, cx: &mut App) {
+    let using_zed_provider = registry
+        .read(cx)
+        .default_model()
+        .map_or(false, |default| default.is_provided_by_zed());
+    if using_zed_provider {
+        ToolRegistry::global(cx).register_tool(WebSearchTool);
+    } else {
+        ToolRegistry::global(cx).unregister_tool(WebSearchTool);
+    }
+}
+
 fn register_edit_file_tool(cx: &mut App) {
     let registry = ToolRegistry::global(cx);
 

crates/web_search_providers/src/web_search_providers.rs

@@ -1,7 +1,7 @@
 mod cloud;
 
 use client::Client;
-use gpui::{App, Context};
+use gpui::{App, Context, Entity};
 use language_model::LanguageModelRegistry;
 use std::sync::Arc;
 use web_search::{WebSearchProviderId, WebSearchRegistry};
@@ -14,31 +14,44 @@ pub fn init(client: Arc<Client>, cx: &mut App) {
 }
 
 fn register_web_search_providers(
-    _registry: &mut WebSearchRegistry,
+    registry: &mut WebSearchRegistry,
     client: Arc<Client>,
     cx: &mut Context<WebSearchRegistry>,
 ) {
+    register_zed_web_search_provider(
+        registry,
+        client.clone(),
+        &LanguageModelRegistry::global(cx),
+        cx,
+    );
+
     cx.subscribe(
         &LanguageModelRegistry::global(cx),
         move |this, registry, event, cx| match event {
             language_model::Event::DefaultModelChanged => {
-                let using_zed_provider = registry
+                register_zed_web_search_provider(this, client.clone(), &registry, cx)
-                    .read(cx)
-                    .default_model()
-                    .map_or(false, |default| default.is_provided_by_zed());
-                if using_zed_provider {
-                    this.register_provider(
-                        cloud::CloudWebSearchProvider::new(client.clone(), cx),
-                        cx,
-                    )
-                } else {
-                    this.unregister_provider(WebSearchProviderId(
-                        cloud::ZED_WEB_SEARCH_PROVIDER_ID.into(),
-                    ));
-                }
             }
             _ => {}
         },
     )
     .detach();
 }
+
+fn register_zed_web_search_provider(
+    registry: &mut WebSearchRegistry,
+    client: Arc<Client>,
+    language_model_registry: &Entity<LanguageModelRegistry>,
+    cx: &mut Context<WebSearchRegistry>,
+) {
+    let using_zed_provider = language_model_registry
+        .read(cx)
+        .default_model()
+        .map_or(false, |default| default.is_provided_by_zed());
+    if using_zed_provider {
+        registry.register_provider(cloud::CloudWebSearchProvider::new(client, cx), cx)
+    } else {
+        registry.unregister_provider(WebSearchProviderId(
+            cloud::ZED_WEB_SEARCH_PROVIDER_ID.into(),
+        ));
+    }
+}