Display index and foreign key details when hovering over a model (#588)

ro-gun · web-flow · commit d63f24573d8a · 2025-03-18T14:49:04.000-04:00
* display index and foreign key details when hovering over a model

* remove italics from heading

* cache index support to avoid repeated rescue
diff --git a/lib/ruby_lsp/ruby_lsp_rails/hover.rb b/lib/ruby_lsp/ruby_lsp_rails/hover.rb
@@ -57,17 +57,38 @@ def generate_column_content(name)
           category: :documentation,
         ) if schema_file
 
-        @response_builder.push(
-          model[:columns].map do |name, type, default_value, nullable|
-            primary_key_suffix = " (PK)" if model[:primary_keys].include?(name)
-            suffixes = []
-            suffixes << "default: #{format_default(default_value, type)}" if default_value
-            suffixes << "not null" unless nullable || primary_key_suffix
-            suffix_string = " - #{suffixes.join(" - ")}" if suffixes.any?
-            "**#{name}**: #{type}#{primary_key_suffix}#{suffix_string}\n"
-          end.join("\n"),
-          category: :documentation,
-        )
+        if model[:columns].any?
+          @response_builder.push(
+            "### Columns",
+            category: :documentation,
+          )
+          @response_builder.push(
+            model[:columns].map do |name, type, default_value, nullable|
+              primary_key_suffix = " (PK)" if model[:primary_keys].include?(name)
+              foreign_key_suffix = " (FK)" if model[:foreign_keys].include?(name)
+              suffixes = []
+              suffixes << "default: #{format_default(default_value, type)}" if default_value
+              suffixes << "not null" unless nullable || primary_key_suffix
+              suffix_string = " - #{suffixes.join(" - ")}" if suffixes.any?
+              "- **#{name}**: #{type}#{primary_key_suffix}#{foreign_key_suffix}#{suffix_string}\n"
+            end.join("\n"),
+            category: :documentation,
+          )
+        end
+
+        if model[:indexes].any?
+          @response_builder.push(
+            "### Indexes",
+            category: :documentation,
+          )
+          @response_builder.push(
+            model[:indexes].map do |index|
+              uniqueness = index[:unique] ? " (unique)" : ""
+              "- **#{index[:name]}** (#{index[:columns].join(",")})#{uniqueness}"
+            end.join("\n"),
+            category: :documentation,
+          )
+        end
       end
 
       #: (String default_value, String type) -> String
diff --git a/lib/ruby_lsp/ruby_lsp_rails/server.rb b/lib/ruby_lsp/ruby_lsp_rails/server.rb
@@ -364,6 +364,8 @@ def resolve_database_info_from_model(model_name)
         info = {
           columns: const.columns.map { |column| [column.name, column.type, column.default, column.null] },
           primary_keys: Array(const.primary_key),
+          foreign_keys: collect_model_foreign_keys(const),
+          indexes: collect_model_indexes(const),
         }
 
         if ActiveRecord::Tasks::DatabaseTasks.respond_to?(:schema_dump_path)
@@ -435,6 +437,36 @@ def clear_file_system_resolver_hooks
           ::ActionView::PathRegistry.file_system_resolver_hooks.clear
         end
       end
+
+      def collect_model_foreign_keys(model)
+        return [] unless model.connection.respond_to?(:supports_foreign_keys?) &&
+          model.connection.supports_foreign_keys?
+
+        model.connection.foreign_keys(model.table_name).map do |key_definition|
+          key_definition.options[:column]
+        end
+      end
+
+      def collect_model_indexes(model)
+        return [] unless database_supports_indexing?(model)
+
+        model.connection.indexes(model.table_name).map do |index_definition|
+          {
+            name: index_definition.name,
+            columns: index_definition.columns,
+            unique: index_definition.unique,
+          }
+        end
+      end
+
+      def database_supports_indexing?(model)
+        return @database_supports_indexing if instance_variable_defined?(:@database_supports_indexing)
+
+        model.connection.indexes(model.table_name)
+        @database_supports_indexing = true
+      rescue NotImplementedError
+        @database_supports_indexing = false
+      end
     end
   end
 end
diff --git a/test/ruby_lsp_rails/hover_test.rb b/test/ruby_lsp_rails/hover_test.rb
@@ -20,6 +20,8 @@ class HoverTest < ActiveSupport::TestCase
             ["active", "boolean", "true", false],
           ],
           primary_keys: ["id"],
+          foreign_keys: ["country_id"],
+          indexes: [{ name: "index_users_on_country_id", columns: ["country_id"], unique: false }],
         }
 
         RunnerClient.any_instance.stubs(model: expected_response)
@@ -41,21 +43,25 @@ class User < ApplicationRecord
 
           [Schema](#{URI::Generic.from_path(path: dummy_root + "/db/schema.rb")})
 
-          **id**: integer (PK)
+          ### Columns
+          - **id**: integer (PK)
 
-          **first_name**: string - default: ""
+          - **first_name**: string - default: ""
 
-          **last_name**: string
+          - **last_name**: string
 
-          **age**: integer - default: 0
+          - **age**: integer - default: 0
 
-          **created_at**: datetime - not null
+          - **created_at**: datetime - not null
 
-          **updated_at**: datetime - not null
+          - **updated_at**: datetime - not null
 
-          **country_id**: integer - not null
+          - **country_id**: integer (FK) - not null
 
-          **active**: boolean - default: true - not null
+          - **active**: boolean - default: true - not null
+
+          ### Indexes
+          - **index_users_on_country_id** (country_id)
         CONTENT
       end
 
@@ -73,6 +79,8 @@ class User < ApplicationRecord
             ["active", "boolean", "true", false],
           ],
           primary_keys: ["id"],
+          foreign_keys: [],
+          indexes: [{ name: "index_users_on_country_id", columns: ["country_id"], unique: true }],
         }
 
         RunnerClient.any_instance.stubs(model: expected_response)
@@ -96,21 +104,25 @@ class User < ApplicationRecord
 
           [Schema](#{URI::Generic.from_path(path: dummy_root + "/db/schema.rb")})
 
-          **id**: integer (PK)
+          ### Columns
+          - **id**: integer (PK)
+
+          - **first_name**: string - default: ""
 
-          **first_name**: string - default: ""
+          - **last_name**: string
 
-          **last_name**: string
+          - **age**: integer - default: 0
 
-          **age**: integer - default: 0
+          - **created_at**: datetime - not null
 
-          **created_at**: datetime - not null
+          - **updated_at**: datetime - not null
 
-          **updated_at**: datetime - not null
+          - **country_id**: integer - not null
 
-          **country_id**: integer - not null
+          - **active**: boolean - default: true - not null
 
-          **active**: boolean - default: true - not null
+          ### Indexes
+          - **index_users_on_country_id** (country_id) (unique)
         CONTENT
       end
 
@@ -125,6 +137,8 @@ class User < ApplicationRecord
             ["updated_at", "datetime"],
           ],
           primary_keys: ["order_id", "product_id"],
+          foreign_keys: [],
+          indexes: [],
         }
 
         RunnerClient.any_instance.stubs(model: expected_response)
@@ -146,15 +160,16 @@ class CompositePrimaryKey < ApplicationRecord
 
           [Schema](#{URI::Generic.from_path(path: dummy_root + "/db/schema.rb")})
 
-          **order_id**: integer (PK)
+          ### Columns
+          - **order_id**: integer (PK)
 
-          **product_id**: integer (PK)
+          - **product_id**: integer (PK)
 
-          **note**: string - not null
+          - **note**: string - not null
 
-          **created_at**: datetime - not null
+          - **created_at**: datetime - not null
 
-          **updated_at**: datetime - not null
+          - **updated_at**: datetime - not null
         CONTENT
       end
 
@@ -163,6 +178,8 @@ class CompositePrimaryKey < ApplicationRecord
           schema_file: "#{dummy_root}/db/structure.sql",
           columns: [],
           primary_keys: [],
+          foreign_keys: [],
+          indexes: [],
         }
 
         RunnerClient.any_instance.stubs(model: expected_response)
@@ -185,6 +202,8 @@ class User < ApplicationRecord
           schema_file: nil,
           columns: [],
           primary_keys: [],
+          foreign_keys: [],
+          indexes: [],
         }
 
         RunnerClient.any_instance.stubs(model: expected_response)
diff --git a/test/ruby_lsp_rails/runner_client_test.rb b/test/ruby_lsp_rails/runner_client_test.rb
@@ -57,8 +57,12 @@ class RunnerClientTest < ActiveSupport::TestCase
             ["active", "boolean", true, false],
           ]
         end
+        foreign_keys = ["country_id"]
+        indexes = [{ name: "index_users_on_country_id", columns: ["country_id"], unique: false }]
         response = T.must(@client.model("User"))
         assert_equal(columns, response.fetch(:columns))
+        assert_equal(foreign_keys, response.fetch(:foreign_keys))
+        assert_equal(indexes, response.fetch(:indexes))
         assert_match(%r{db/schema\.rb$}, response.fetch(:schema_file))
       end
 
