feat(builtin): add validate attribute on pkg_npm

Currently just validates that the package_name attribute matches the name in package.json (if there is one)

Fixes bazel-contrib#2782

internal/pkg_npm/packager.js

@@ -93,7 +93,7 @@ function main(args) {
   args = fs.readFileSync(args[0], {encoding: 'utf-8'}).split('\n').map(unquoteArgs);
   const
       [outDir, baseDir, srcsArg, binDir, genDir, depsArg, packagesArg, substitutionsArg,
-       volatileFile, infoFile, vendorExternalArg] = args;
+       volatileFile, infoFile, vendorExternalArg, target, validate, packageNameArg] = args;
 
   const substitutions = [
     // Strip content between BEGIN-INTERNAL / END-INTERNAL comments
@@ -140,6 +140,21 @@ function main(args) {
             `${src} in 'srcs' does not reside in the base directory, ` +
             `generated file should belong in 'deps' instead.`);
       }
+
+      if (validate === "true" && path.relative(baseDir, src) === "package.json") {
+        const packageJson = JSON.parse(fs.readFileSync(src));
+        if (packageJson['name'] !== packageNameArg) {
+          console.error(`ERROR: pkg_npm rule ${
+            target} was configured with attributes that don't match the package.json`);
+          console.error(` - attribute package_name=${packageNameArg} does not match package.json name=${packageJson['name']}`)
+          console.error('You can automatically fix this by running:');
+          console.error(
+              `    npx @bazel/buildozer 'set package_name "${packageJson['name']}"' ${target}`);
+          console.error('Or to suppress this error, run:');
+          console.error(`    npx @bazel/buildozer 'set validate False' ${target}`);
+          return 1;
+        }
+      }
       copyWithReplace(src, path.join(outDir, path.relative(baseDir, src)), substitutions);
     }
   }

internal/pkg_npm/pkg_npm.bzl

@@ -129,6 +129,11 @@ See the section on stamping in the [README](stamping)
         NOTE: If this attribute is set, a valid `package.json` file must be included in the sources of this target
         """,
     ),
+    "validate": attr.bool(
+        doc = "Whether to check that the attributes match the package.json",
+        # TODO(4.0) flip default to True
+        default = False,
+    ),
     "vendor_external": attr.string_list(
         doc = """External workspaces whose contents should be vendored into this workspace.
         Avoids `external/foo` path segments in the resulting package.""",
@@ -245,6 +250,9 @@ def create_package(ctx, deps_files, nested_packages):
         args.add_all(["", ""])
 
     args.add_joined(ctx.attr.vendor_external, join_with = ",", omit_if_empty = False)
+    args.add(str(ctx.label))
+    args.add(ctx.attr.validate)
+    args.add(ctx.attr.package_name)
 
     ctx.actions.run(
         progress_message = "Assembling npm package %s" % package_dir.short_path,

internal/pkg_npm/test/BUILD.bazel

@@ -40,6 +40,7 @@ node_context_data(
 
 pkg_npm(
     name = "test_pkg",
+    package_name = "test-pkg",
     srcs = [
         "package.json",
         "some_file",

internal/pkg_npm/test/linking/bar/BUILD.bazel

@@ -19,5 +19,6 @@ pkg_npm(
         "main.js",
         "package.json",
     ],
+    validate = False,
     visibility = ["//internal/pkg_npm/test/linking:__pkg__"],
 )

internal/pkg_npm/test/linking/feb/BUILD.bazel

@@ -21,6 +21,7 @@ pkg_npm(
     name = "scoped_feb",
     package_name = "@scoped/feb",
     srcs = ["package.json"],
+    validate = False,
     visibility = ["//internal/pkg_npm/test/linking:__pkg__"],
     deps = [":feb_lib"],
 )

internal/pkg_npm/test/linking/fez/BUILD.bazel

@@ -18,6 +18,7 @@ pkg_npm(
 pkg_npm(
     name = "scoped_fez",
     package_name = "@scoped/fez",
+    validate = False,
     visibility = ["//internal/pkg_npm/test/linking:__pkg__"],
     deps = [":fez_lib"],
 )

internal/pkg_npm/test/linking/foo/BUILD.bazel

@@ -36,6 +36,7 @@ pkg_npm(
 pkg_npm(
     name = "scoped_foo",
     package_name = "@scoped/foo",
+    validate = False,
     visibility = ["//internal/pkg_npm/test/linking:__pkg__"],
     deps = [":scoped_foo_lib"],
 )

internal/pkg_npm/test/linking/fub/BUILD.bazel

@@ -32,6 +32,7 @@ pkg_npm(
     name = "scoped_fub",
     package_name = "@scoped/fub",
     srcs = ["package.json"],
+    validate = False,
     visibility = ["//internal/pkg_npm/test/linking:__pkg__"],
     deps = [":fub_lib"],
 )

internal/pkg_npm/test/tgz_out/BUILD.bazel

@@ -2,6 +2,7 @@ load("@build_bazel_rules_nodejs//:index.bzl", "pkg_npm")
 
 pkg_npm(
     name = "pkg",
+    package_name = "awesome-package",
     srcs = [
         "main.js",
         "package.json",