enable and fix a number of lints

pkgs/pool/analysis_options.yaml

diff --git a/pkgs/pool/analysis_options.yaml b/pkgs/pool/analysis_options.yaml
index 749f62a..f8eebb4 100644
--- a/pkgs/pool/analysis_options.yaml
+++ b/pkgs/pool/analysis_options.yaml
@@ -4,8 +4,80 @@
     implicit-casts: false
 linter:
   rules:
+    - always_declare_return_types
+    - annotate_overrides
+    - avoid_empty_else
+    - avoid_function_literals_in_foreach_calls
+    - avoid_init_to_null
+    - avoid_null_checks_in_equality_operators
+    - avoid_relative_lib_imports
+    - avoid_renaming_method_parameters
+    - avoid_return_types_on_setters
+    - avoid_returning_null
+    - avoid_returning_null_for_future
+    - avoid_shadowing_type_parameters
+    - avoid_types_as_parameter_names
+    - avoid_unused_constructor_parameters
     - await_only_futures
+    - camel_case_types
+    - cancel_subscriptions
+    - comment_references
+    - constant_identifier_names
+    - control_flow_in_finally
+    - directives_ordering
+    - empty_catches
+    - empty_constructor_bodies
+    - empty_statements
+    - hash_and_equals
     - implementation_imports
+    - invariant_booleans
+    - iterable_contains_unrelated_type
+    - library_names
+    - library_prefixes
+    - list_remove_unrelated_type
+    - literal_only_boolean_expressions
+    - no_adjacent_strings_in_list
+    - no_duplicate_case_values
+    - non_constant_identifier_names
+    - null_closures
+    - omit_local_variable_types
+    - only_throw_errors
+    - overridden_fields
+    - package_api_docs
+    - package_names
+    - package_prefixed_library_names
+    - prefer_adjacent_string_concatenation
+    - prefer_collection_literals
+    - prefer_conditional_assignment
+    - prefer_const_constructors
+    - prefer_contains
+    - prefer_equal_for_default_values
+    - prefer_final_fields
+    #- prefer_final_locals
+    - prefer_initializing_formals
+    - prefer_interpolation_to_compose_strings
+    - prefer_is_empty
+    - prefer_is_not_empty
+    #- prefer_single_quotes
     - prefer_typing_uninitialized_variables
+    - recursive_getters
+    - slash_for_doc_comments
+    - super_goes_last
+    - test_types_in_equals
+    - throw_in_finally
+    - type_init_formals
+    - unawaited_futures
+    - unnecessary_await_in_return
+    - unnecessary_brace_in_string_interps
     - unnecessary_const
+    - unnecessary_getters_setters
+    - unnecessary_lambdas
     - unnecessary_new
+    - unnecessary_null_aware_assignments
+    - unnecessary_parenthesis
+    - unnecessary_statements
+    - unnecessary_this
+    - unrelated_type_equality_checks
+    - use_function_type_syntax_for_parameters
+    - use_rethrow_when_possible
+    - valid_regexps

pkgs/pool/lib/pool.dart

diff --git a/pkgs/pool/lib/pool.dart b/pkgs/pool/lib/pool.dart
index 6994c76..a97ec75 100644
--- a/pkgs/pool/lib/pool.dart
+++ b/pkgs/pool/lib/pool.dart
@@ -117,7 +117,7 @@
   /// Future.
   ///
   /// The return value of [callback] is piped to the returned Future.
-  Future<T> withResource<T>(FutureOr<T> callback()) async {
+  Future<T> withResource<T>(FutureOr<T> Function() callback) async {
     if (isClosed) {
       throw StateError("withResource() may not be called on a closed Pool.");
     }
@@ -174,7 +174,7 @@
 
   /// If there are any pending requests, this will fire the oldest one after
   /// running [onRelease].
-  void _onResourceReleaseAllowed(onRelease()) {
+  void _onResourceReleaseAllowed(Function() onRelease) {
     _resetTimer();
 
     if (_requestedResources.isNotEmpty) {
@@ -196,7 +196,7 @@
   ///
   /// Futures returned by [_runOnRelease] always complete in the order they were
   /// created, even if earlier [onRelease] callbacks take longer to run.
-  Future<PoolResource> _runOnRelease(onRelease()) {
+  Future<PoolResource> _runOnRelease(Function() onRelease) {
     Future.sync(onRelease).then((value) {
       _onReleaseCompleters.removeFirst().complete(PoolResource._(this));
     }).catchError((error, StackTrace stackTrace) {
@@ -242,7 +242,7 @@
 class PoolResource {
   final Pool _pool;
 
-  /// Whether [this] has been released yet.
+  /// Whether `this` has been released yet.
   bool _released = false;
 
   PoolResource._(this._pool);
@@ -269,7 +269,7 @@
   /// This is useful when a resource's main function is complete, but it may
   /// produce additional information later on. For example, an isolate's task
   /// may be complete, but it could still emit asynchronous errors.
-  void allowRelease(onRelease()) {
+  void allowRelease(Function() onRelease) {
     if (_released) {
       throw StateError("A PoolResource may only be released once.");
     }

pkgs/pool/test/pool_test.dart

diff --git a/pkgs/pool/test/pool_test.dart b/pkgs/pool/test/pool_test.dart
index 66624cf..6c9d0a5 100644
--- a/pkgs/pool/test/pool_test.dart
+++ b/pkgs/pool/test/pool_test.dart
@@ -161,7 +161,7 @@
         for (var i = 0; i < 50; i++) {
           expect(pool.request(), completes);
         }
-        expect(pool.request(), throwsA(TypeMatcher<TimeoutException>()));
+        expect(pool.request(), throwsA(const TypeMatcher<TimeoutException>()));
 
         async.elapse(Duration(seconds: 6));
       });
@@ -456,7 +456,7 @@
 ///
 /// This should only be called within a [FakeAsync.run] zone.
 Matcher get doesNotComplete => predicate((future) {
-      expect(future, TypeMatcher<Future>());
+      expect(future, const TypeMatcher<Future>());
 
       var stack = Trace.current(1);
       future.then((_) => registerException(