fix: ensure that pnpm install behaviour is consistent with other pa…

…ckage managers, even in CI

lib/package_json/managers/pnpm_like.rb

@@ -108,7 +108,15 @@ def with_native_args(
       )
         args = [*extra_args]
 
-        args << "--frozen-lockfile" if frozen
+        # we make frozen lockfile behaviour consistent with the other package managers
+        # as pnpm automatically enables frozen lockfile if it detects it's running in CI
+        unless frozen.nil?
+          flag = "--no-frozen-lockfile"
+          flag = "--frozen-lockfile" if frozen
+
+          args << flag
+        end
+
         args << "--ignore-scripts" if ignore_scripts
         args << "--no-optional" if omit_optional_deps
 

spec/package_json/managers/pnpm_like_spec.rb

@@ -22,7 +22,7 @@
       with_package_json_file do
         manager.install
 
-        expect_manager_to_be_invoked_with("install")
+        expect_manager_to_be_invoked_with("install --no-frozen-lockfile")
       end
     end
 
@@ -42,23 +42,23 @@
         with_package_json_file do
           manager.install(ignore_scripts: true)
 
-          expect_manager_to_be_invoked_with("install --ignore-scripts")
+          expect_manager_to_be_invoked_with("install --no-frozen-lockfile --ignore-scripts")
         end
       end
 
       it "supports legacy_peer_deps" do
         with_package_json_file do
           manager.install(legacy_peer_deps: true)
 
-          expect_manager_to_be_invoked_with("install")
+          expect_manager_to_be_invoked_with("install --no-frozen-lockfile")
         end
       end
 
       it "supports omit_optional_deps" do
         with_package_json_file do
           manager.install(omit_optional_deps: true)
 
-          expect_manager_to_be_invoked_with("install --no-optional")
+          expect_manager_to_be_invoked_with("install --no-frozen-lockfile --no-optional")
         end
       end
 
@@ -82,7 +82,7 @@
 
   describe "#native_install_command" do
     it "returns the full command" do
-      expect(manager.native_install_command).to eq("#{package_manager_cmd} install")
+      expect(manager.native_install_command).to eq("#{package_manager_cmd} install --no-frozen-lockfile")
     end
 
     context "when passing the usual options" do
@@ -94,19 +94,19 @@
 
       it "supports ignore_scripts" do
         expect(manager.native_install_command(ignore_scripts: true)).to eq(
-          "#{package_manager_cmd} install --ignore-scripts"
+          "#{package_manager_cmd} install --no-frozen-lockfile --ignore-scripts"
         )
       end
 
       it "supports legacy_peer_deps" do
         expect(manager.native_install_command(legacy_peer_deps: true)).to eq(
-          "#{package_manager_cmd} install"
+          "#{package_manager_cmd} install --no-frozen-lockfile"
         )
       end
 
       it "supports omit_optional_deps" do
         expect(manager.native_install_command(omit_optional_deps: true)).to eq(
-          "#{package_manager_cmd} install --no-optional"
+          "#{package_manager_cmd} install --no-frozen-lockfile --no-optional"
         )
       end