From f49530f9b7522afc3bc1c579ea53f748a96ee36c Mon Sep 17 00:00:00 2001
From: Samuel K <skevetter@pm.me>
Date: Sun, 3 May 2026 01:42:04 -0500
Subject: [PATCH] feat(config): support custom workspaceMount from
 devcontainer.json
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add unit tests for getWorkspace() covering custom mount, default mount,
default mount with workspaceFolder, and empty/unset workspaceMount.
Add E2E test validating custom workspace mount with testdata.

The workspaceMount field was already wired through config parsing and
container creation — this commit adds test coverage for the feature.
---
 e2e/tests/up/provider_docker.go               | 25 +++++++
 .../docker-workspace-mount/.devcontainer.json |  6 ++
 pkg/devcontainer/run_test.go                  | 68 +++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 e2e/tests/up/testdata/docker-workspace-mount/.devcontainer.json

diff --git a/e2e/tests/up/provider_docker.go b/e2e/tests/up/provider_docker.go
index 57d950a7d..361be75b1 100644
--- a/e2e/tests/up/provider_docker.go
+++ b/e2e/tests/up/provider_docker.go
@@ -528,6 +528,31 @@ var _ = ginkgo.Describe(
 				To(gomega.ContainElement("apparmor=unconfined"))
 		}, ginkgo.SpecTimeout(framework.TimeoutShort()))
 
+		ginkgo.It("custom workspace mount", func(ctx context.Context) {
+			tempDir, err := dtc.setupAndUp(ctx, "tests/up/testdata/docker-workspace-mount")
+			framework.ExpectNoError(err)
+
+			workspace, err := dtc.f.FindWorkspace(ctx, tempDir)
+			framework.ExpectNoError(err)
+
+			ids, err := dtc.findWorkspaceContainer(ctx, workspace)
+			framework.ExpectNoError(err)
+			gomega.Expect(ids).To(gomega.HaveLen(1))
+
+			var details []container.InspectResponse
+			err = dtc.dockerHelper.Inspect(ctx, ids, "container", &details)
+			framework.ExpectNoError(err)
+
+			hasCustomMount := false
+			for _, m := range details[0].Mounts {
+				if m.Destination == "/custom-workspace" {
+					hasCustomMount = true
+					break
+				}
+			}
+			gomega.Expect(hasCustomMount).To(gomega.BeTrue())
+		}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
 		ginkgo.It("multi devcontainer selection", func(ctx context.Context) {
 			tempDir, err := setupWorkspace(
 				"tests/up/testdata/docker-multi-devcontainer",
diff --git a/e2e/tests/up/testdata/docker-workspace-mount/.devcontainer.json b/e2e/tests/up/testdata/docker-workspace-mount/.devcontainer.json
new file mode 100644
index 000000000..e24babbdb
--- /dev/null
+++ b/e2e/tests/up/testdata/docker-workspace-mount/.devcontainer.json
@@ -0,0 +1,6 @@
+{
+  "name": "Go",
+  "image": "ghcr.io/devsy-org/test-images/go:1",
+  "workspaceMount": "type=bind,source=${localWorkspaceFolder},target=/custom-workspace",
+  "workspaceFolder": "/custom-workspace"
+}
diff --git a/pkg/devcontainer/run_test.go b/pkg/devcontainer/run_test.go
index 1f9746a16..ffe987e8c 100644
--- a/pkg/devcontainer/run_test.go
+++ b/pkg/devcontainer/run_test.go
@@ -130,3 +130,71 @@ func searchString(s, substr string) bool {
 	}
 	return false
 }
+
+func TestGetWorkspace_CustomWorkspaceMount(t *testing.T) {
+	customMount := "type=bind,source=/host/src,target=/custom-ws"
+	conf := &config.DevContainerConfig{
+		NonComposeBase: config.NonComposeBase{
+			WorkspaceMount: customMount,
+		},
+	}
+
+	mount, folder := getWorkspace("/ignored", "ws-id", conf)
+
+	if mount != customMount {
+		t.Fatalf("expected raw workspaceMount string, got %q", mount)
+	}
+	if folder != "/custom-ws" {
+		t.Fatalf("expected target /custom-ws, got %q", folder)
+	}
+}
+
+func TestGetWorkspace_DefaultMount(t *testing.T) {
+	conf := &config.DevContainerConfig{}
+
+	mount, folder := getWorkspace("/home/user/project", "abc123", conf)
+
+	if !contains(mount, "type=bind") || !contains(mount, "source=/home/user/project") {
+		t.Fatalf("expected bind mount with source, got %q", mount)
+	}
+	if !contains(mount, "target=/workspaces/abc123") {
+		t.Fatalf("expected target /workspaces/abc123, got %q", mount)
+	}
+	if folder != "/workspaces/abc123" {
+		t.Fatalf("expected /workspaces/abc123, got %q", folder)
+	}
+}
+
+func TestGetWorkspace_DefaultMountWithWorkspaceFolder(t *testing.T) {
+	conf := &config.DevContainerConfig{
+		DevContainerConfigBase: config.DevContainerConfigBase{
+			WorkspaceFolder: "/app",
+		},
+	}
+
+	mount, folder := getWorkspace("/home/user/project", "ws-id", conf)
+
+	if !contains(mount, "type=bind") || !contains(mount, "target=/app") {
+		t.Fatalf("expected bind mount with target /app, got %q", mount)
+	}
+	if folder != "/app" {
+		t.Fatalf("expected /app, got %q", folder)
+	}
+}
+
+func TestGetWorkspace_EmptyWorkspaceMount(t *testing.T) {
+	conf := &config.DevContainerConfig{
+		NonComposeBase: config.NonComposeBase{
+			WorkspaceMount: "",
+		},
+	}
+
+	mount, folder := getWorkspace("/home/user/project", "ws-id", conf)
+
+	if folder != "/workspaces/ws-id" {
+		t.Fatalf("expected default folder, got %q", folder)
+	}
+	if !contains(mount, "type=bind") {
+		t.Fatalf("expected default bind mount, got %q", mount)
+	}
+}