Support for resolving package config and pubspec.lock in workspaces (#…

…3684)

Instead of expecting pubspec.lock and .dart_tool/package_config.json to reside in the same folder as pubspec.yaml, we visit each parent of the current directory until we find a .dart_tool/package_config.json, and expect pubspec.lock to exist next to that.

Also invoke the generated scripts with an explicit packageConfig.

This is to support running build_runner build in a workspace package, as implemented in dart-lang/pub#4127

---------

Co-authored-by: Jake Macdonald <jakemac@google.com>

build_runner/CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 2.4.11-wip
 
+- Explicitly pass the current isolates package config instead of assuming the
+  location, to support the upcoming pub workspaces feature.
+
 ## 2.4.10
 
 - Support version `1.x` and `2.x` of `shelf_web_socket` and `2.x` and `3.x`

build_runner/lib/src/build_script_generate/bootstrap.dart

@@ -164,6 +164,7 @@ Future<int> _createKernelIfNeeded(
       'lib/_internal/vm_platform_strong.dill',
       enabledExperiments: experiments,
       printIncrementalDependencies: false,
+      packagesJson: (await Isolate.packageConfig)!.toFilePath(),
     );
 
     var hadOutput = false;

build_runner_core/CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 7.3.1-wip
 
+- Support the upcoming pub workspaces feature.
 - Bump the min sdk to 3.4.0.
 - Remove some unnecessary casts and non-null assertions now that we have private
   field promotion.

build_runner_core/lib/src/package_graph/package_graph.dart

@@ -78,14 +78,35 @@ class PackageGraph {
           'pubspec.yaml.');
     }
 
-    final packageConfig =
-        await findPackageConfig(Directory(packagePath), recurse: false);
+    // The path of the directory that contains .dart_tool/package_config.json.
+    //
+    // Should also contain `pubspec.lock`.
+    var rootDir = packagePath;
+    PackageConfig? packageConfig;
+    // Manually recurse through parent directories, to obtain the [rootDir]
+    // where a package config was found. It doesn't seem possible to obtain this
+    // directly with package:package_config.
+    while (true) {
+      packageConfig =
+          await findPackageConfig(Directory(rootDir), recurse: false);
+      File(p.join(rootDir, '.dart_tool', 'package_config.json'));
+      if (packageConfig != null) {
+        break;
+      }
+      final next = p.dirname(rootDir);
+      if (next == rootDir) {
+        // We have reached the file system root.
+        break;
+      }
+      rootDir = next;
+    }
+
     if (packageConfig == null) {
       throw StateError(
           'Unable to find package config for package at $packagePath.');
     }
 
-    final dependencyTypes = _parseDependencyTypes(packagePath);
+    final dependencyTypes = _parseDependencyTypes(rootDir);
 
     final nodes = <String, PackageNode>{};
     // A consistent package order _should_ mean a consistent order of build
@@ -94,11 +115,13 @@ class PackageGraph {
     final consistentlyOrderedPackages = packageConfig.packages.toList()
       ..sort((a, b) => a.name.compareTo(b.name));
     for (final package in consistentlyOrderedPackages) {
-      var isRoot = package.name == rootPackageName;
+      final isRoot = package.name == rootPackageName;
       nodes[package.name] = PackageNode(
           package.name,
           package.root.toFilePath(),
-          isRoot ? DependencyType.path : dependencyTypes[package.name],
+          // If the package is missing from pubspec.lock, assume it is a path
+          // dependency.
+          dependencyTypes[package.name] ?? DependencyType.path,
           package.languageVersion,
           isRoot: isRoot);
     }

build_runner_core/test/fixtures/workspace/.dart_tool/package_config.json

@@ -0,0 +1,23 @@
+{
+  "configVersion": 2,
+  "packages": [
+    {
+      "name": "workspace",
+      "rootUri": "../",
+      "packageUri": "lib/",
+      "languageVersion": "3.5"
+    },
+    {
+      "name": "a",
+      "rootUri": "../pkgs/a",
+      "packageUri": "lib/",
+      "languageVersion": "3.5"
+    },
+    {
+      "name": "b",
+      "rootUri": "../pkgs/b",
+      "packageUri": "lib/",
+      "languageVersion": "3.5"
+    }
+  ]
+}

build_runner_core/test/fixtures/workspace/.gitignore

@@ -0,0 +1,5 @@
+# Take special care to include the .dart_tool/package_config.json
+#
+!.dart_tool
+.dart_tool/*
+!.dart_tool/package_config.json

build_runner_core/test/fixtures/workspace/pkgs/a/pubspec.yaml

@@ -0,0 +1,6 @@
+name: a
+environment:
+  sdk: ^3.5.0-0
+resolution: workspace
+dependencies:
+  b:

build_runner_core/test/fixtures/workspace/pkgs/b/pubspec.yaml

@@ -0,0 +1,4 @@
+name: b
+environment:
+  sdk: ^3.5.0-0
+resolution: workspace

build_runner_core/test/fixtures/workspace/pubspec.lock

@@ -0,0 +1,5 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages: {}
+sdks:
+  dart: ">=3.5.0-0 <4.0.0"

build_runner_core/test/fixtures/workspace/pubspec.yaml

@@ -0,0 +1,6 @@
+name: workspace
+environment:
+  sdk: ^3.5.0-0
+workspace:
+  - pkgs/a
+  - pkgs/b

build_runner_core/test/package_graph/package_graph_test.dart

@@ -154,6 +154,42 @@ void main() {
           throwsA(anything));
     });
   });
+
+  group('workspace ', () {
+    var workspaceFixturePath = 'test/fixtures/workspace';
+
+    test('Loads all packages in workspace. Has correct root', () async {
+      Matcher packageNodeEquals(PackageNode node) => isA<PackageNode>()
+          .having((c) => c.path, 'path', node.path)
+          .having((c) => c.dependencies, 'dependencies',
+              node.dependencies.map(packageNodeEquals))
+          .having(
+              (c) => c.dependencyType, 'dependencyType', node.dependencyType);
+
+      final graph = await PackageGraph.forPath('$workspaceFixturePath/pkgs/a');
+      var a = PackageNode(
+          'a', '$workspaceFixturePath/pkgs/a', DependencyType.path, null,
+          isRoot: true);
+      var b = PackageNode(
+          'b', '$workspaceFixturePath/pkgs/b', DependencyType.path, null);
+      a.dependencies.add(b);
+      var workspace = PackageNode(
+        'workspace',
+        workspaceFixturePath,
+        DependencyType.path,
+        null,
+      );
+
+      expect(graph.allPackages, {
+        'a': packageNodeEquals(a),
+        'b': packageNodeEquals(b),
+        'workspace': packageNodeEquals(workspace),
+        r'$sdk': anything
+      });
+
+      expect(graph.root, packageNodeEquals(a));
+    });
+  });
 }
 
 void expectPkg(PackageNode node, String name, String location,