Migrate to null safety

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 2.0.0
+
+- Migrate to null safety.
+- Remove legacy APIs.
+
 ## 1.9.3
 
 - Fix `Package` constructor not accepting relative `packageUriRoot`.

README.md

@@ -7,11 +7,12 @@ in the Package Configuration v2 [design document](https://github.com/dart-lang/l
 The primary libraries are
 * `package_config.dart`:
     Defines the `PackageConfig` class and other types needed to use
-    package configurations.
+    package configurations, and provides functions to find, read and
+    write package configuration files.
 
-* `package_config_discovery.dart`:
-    Provides functions for reading configurations from files,
-    and writing them back out.
+* `package_config_types.dart`:
+    Just the `PackageConfig` class and other types needed to use
+    package configurations. This library does not depend on `dart:io`.
 
 The package includes deprecated backwards compatible functionality to
 work with the `.packages` file. This functionality will not be maintained,

analysis_options.yaml

@@ -6,6 +6,5 @@ include: package:pedantic/analysis_options.1.9.0.yaml
 analyzer:
   errors:
     annotate_overrides: ignore
-    curly_braces_in_flow_control_structures: ignore
     prefer_single_quotes: ignore
     use_function_type_syntax_for_parameters: ignore