fix: issue with reading context when not provided

src/__tests__/fixtures/get-and-set/__snapshots__/get-read-assign-to-missing-context/node.render.expected.html

@@ -0,0 +1,4 @@
+<div />
+<button>
+  increment
+</button>

src/__tests__/fixtures/get-and-set/__snapshots__/get-read-assign-to-missing-context/web.render.expected.html

@@ -0,0 +1,4 @@
+<div />
+<button>
+  increment
+</button>

src/__tests__/fixtures/get-and-set/__snapshots__/get-read-assign-to-missing-context/web.step-0.error.expected.txt

@@ -0,0 +1 @@
+Assignment to constant variable.

src/__tests__/fixtures/get-and-set/index.test.ts

@@ -8,6 +8,15 @@ describe(
   fixture("./templates/self-reference.marko")
 );
 
+describe(
+  "<get> read & assign to missing context",
+  fixture("./templates/missing-context.marko", [
+    async ({ screen, fireEvent }) => {
+      await fireEvent.click(screen.getByText("increment"));
+    },
+  ])
+);
+
 describe(
   "<get> & <set> assign to mutable set",
   fixture("./templates/assign-to-mutable-set.marko", [

src/__tests__/fixtures/get-and-set/templates/missing-context.marko

@@ -0,0 +1,3 @@
+<get/val="."/>
+<div>${val}</div>
+<button onClick=(() => val++)>increment</button>

src/components/get/index.marko

@@ -47,4 +47,5 @@ class {
   }
 }
 
-<${input.renderBody}(component.data.default, component.data.defaultChange)/>
+$ var data = component.data || {};
+<${input.renderBody}(data.default, data.defaultChange)/>