diff --git a/tests/roundtrip_test.go b/tests/roundtrip_test.go
new file mode 100644
index 000000000000..4617519969fc
--- /dev/null
+++ b/tests/roundtrip_test.go
@@ -0,0 +1,184 @@
+// Copyright 2016-2021, Pulumi Corporation.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// nolint: lll
+package tests
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/hexops/autogold"
+	"github.com/stretchr/testify/require"
+
+	"github.com/pulumi/pulumi/pkg/v3/testing/integration"
+	ptesting "github.com/pulumi/pulumi/sdk/v3/go/common/testing"
+	"github.com/pulumi/pulumi/sdk/v3/go/common/workspace"
+)
+
+func TestProjectRoundtripComments(t *testing.T) {
+	t.Parallel()
+
+	e := ptesting.NewEnvironment(t)
+	defer func() {
+		if !t.Failed() {
+			e.DeleteEnvironment()
+		}
+	}()
+
+	pulumiProject := `
+# 🔴 header comment
+name: pulumi-test
+runtime: yaml
+config:
+  first-value:
+    type: string
+    default: first
+  second-value:
+    type: string
+  third-value:
+    type: array
+    items:
+      type: string
+    default: [third] # 🟠 comment after array
+# 🟡 comment before resources
+resources:
+  my-bucket:
+            type: aws:s3:bucket
+            # 🟢 comment before props, note the indentation is excessive, will change to 2 spaces
+            properties:
+              # 🔵 comment before prop
+              bucket: test-123 # 🟣 comment after prop
+# 🟥 footer comment
+`
+
+	integration.CreatePulumiRepo(e, pulumiProject)
+	projFilename := filepath.Join(e.CWD, fmt.Sprintf("%s.yaml", workspace.ProjectFile))
+	// TODO: Replace this with config set --project after implemented.
+	proj, err := workspace.LoadProject(projFilename)
+	require.NoError(t, err)
+	ty := "string"
+	proj.Config["new-value"] = workspace.ProjectConfigType{
+		Type:        &ty,
+		Description: "💜 a new value added to config, expect unicode to be escaped",
+	}
+	err = proj.Save(projFilename)
+	require.NoError(t, err)
+
+	projData, err := os.ReadFile(projFilename)
+	require.NoError(t, err)
+
+	// Project file:
+	want := autogold.Want("roundtrip-project", `# 🔴 header comment
+name: pulumi-test
+runtime: yaml
+config:
+  first-value:
+    type: string
+    default: first
+  new-value:
+    type: string
+    description: "\U0001F49C a new value added to config, expect unicode to be escaped"
+  second-value:
+    type: string
+  third-value:
+    type: array
+    items:
+      type: string
+    default: [third] # 🟠 comment after array
+# 🟡 comment before resources
+resources:
+  my-bucket:
+    # 🟢 comment before props, note the indentation is excessive, will change to 2 spaces
+    properties:
+      # 🔵 comment before prop
+      bucket: test-123 # 🟣 comment after prop
+    type: aws:s3:bucket
+# 🟥 footer comment
+`)
+	want.Equal(t, string(projData))
+}
+
+func TestConfigRoundtripComments(t *testing.T) {
+	t.Parallel()
+
+	e := ptesting.NewEnvironment(t)
+	defer func() {
+		if !t.Failed() {
+			e.DeleteEnvironment()
+		}
+	}()
+
+	pulumiProject := `
+name: foo
+runtime: yaml
+`
+
+	integration.CreatePulumiRepo(e, pulumiProject)
+	e.SetBackend(e.LocalURL())
+	e.RunCommand("pulumi", "stack", "init", "test")
+	e.Passphrase = "TestConfigRoundtripComments"
+	configFilename := filepath.Join(e.CWD, fmt.Sprintf("%s.test.yaml", workspace.ProjectFile))
+
+	err := os.WriteFile(configFilename, []byte(`
+encryptionsalt: v1:ThS5UPxP9qc=:v1:UZYAXF+ylaJ0rGhv:9OTvBnOEDFgxs7btjzSu+LZ470vLpg==
+# 🔴 header comment
+config:
+  foo:a: some-value # 🟠 comment after value
+  # 🟡 comment before key
+  foo:b: some-value
+  foo:c:
+    a: A
+    b: B
+    c:
+      - 1
+      - 2
+      - 3 # 🟢 comment in array
+      # 🔵 comment after array
+  foo:d:
+    secure: v1:T1ftqhY0hqr+EJK6:+jvd5PMecFx80tcavzuZY4tLatgIfoe/xR72GA== # 🟣 comment on secret
+
+# 🟥 footer comment`), 0600)
+	require.NoError(t, err)
+	e.RunCommand("pulumi", "config", "set", "e", "E")
+	e.RunCommand("pulumi", "config", "set", "--path", "c.c[2]", "three")
+
+	projData, err := os.ReadFile(configFilename)
+	require.NoError(t, err)
+
+	// Project file:
+	want := autogold.Want("roundtrip-config", `encryptionsalt: v1:ThS5UPxP9qc=:v1:UZYAXF+ylaJ0rGhv:9OTvBnOEDFgxs7btjzSu+LZ470vLpg==
+# 🔴 header comment
+config:
+  foo:a: some-value # 🟠 comment after value
+  # 🟡 comment before key
+  foo:b: some-value
+  foo:c:
+    a: A
+    b: B
+    c:
+      - 1
+      - 2
+      - three # 🟢 comment in array
+      # 🔵 comment after array
+  foo:d:
+    secure: v1:T1ftqhY0hqr+EJK6:+jvd5PMecFx80tcavzuZY4tLatgIfoe/xR72GA== # 🟣 comment on secret
+  foo:e: E
+
+# 🟥 footer comment
+`)
+	want.Equal(t, string(projData))
+}