diff --git a/tests/snapshots.rs b/tests/snapshots.rs
index 6ceb0ad1b4..453a078b3e 100644
--- a/tests/snapshots.rs
+++ b/tests/snapshots.rs
@@ -116,3 +116,9 @@ fn converts_wgsl_quad() {
 fn converts_wgsl_simple() {
     convert_wgsl("simple");
 }
+
+#[cfg(feature = "wgsl-in")]
+#[test]
+fn converts_wgsl_function() {
+    convert_wgsl("function");
+}
diff --git a/tests/snapshots/in/function.param.ron b/tests/snapshots/in/function.param.ron
new file mode 100644
index 0000000000..4adad36220
--- /dev/null
+++ b/tests/snapshots/in/function.param.ron
@@ -0,0 +1,5 @@
+(
+	spv_capabilities: [ Shader ],
+	mtl_bindings: {
+	}
+)
diff --git a/tests/snapshots/in/function.wgsl b/tests/snapshots/in/function.wgsl
new file mode 100644
index 0000000000..12549c7f97
--- /dev/null
+++ b/tests/snapshots/in/function.wgsl
@@ -0,0 +1,8 @@
+fn test_function(test: f32) -> f32 {
+    return test;
+}
+
+[[stage(vertex)]]
+fn main() -> void {
+    var test: f32 = test_function(1.0);
+}
diff --git a/tests/snapshots/snapshots__function.msl.snap b/tests/snapshots/snapshots__function.msl.snap
new file mode 100644
index 0000000000..cbaab56341
--- /dev/null
+++ b/tests/snapshots/snapshots__function.msl.snap
@@ -0,0 +1,27 @@
+---
+source: tests/snapshots.rs
+expression: msl
+---
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+typedef float type;
+
+type test_function(
+	type test
+) {
+	return test;
+}
+struct main1Input {
+};
+struct main1Output {
+};
+vertex main1Output main1(
+	main1Input input [[stage_in]]
+) {
+	main1Output output;
+	type test1;
+	test1 = test_function(1.0);
+	return output;
+}
+
diff --git a/tests/snapshots/snapshots__function.spvasm.snap b/tests/snapshots/snapshots__function.spvasm.snap
new file mode 100644
index 0000000000..a28f333e15
--- /dev/null
+++ b/tests/snapshots/snapshots__function.spvasm.snap
@@ -0,0 +1,31 @@
+---
+source: tests/snapshots.rs
+expression: dis
+---
+; SPIR-V
+; Version: 1.0
+; Generator: rspirv
+; Bound: 16
+OpCapability Shader
+%1 = OpExtInstImport "GLSL.std.450"
+OpMemoryModel Logical GLSL450
+OpEntryPoint Vertex %11 "main"
+%2 = OpTypeFloat 32
+%4 = OpTypePointer Function %2
+%6 = OpTypeFunction %2 %4
+%10 = OpTypeVoid
+%12 = OpTypeFunction %10
+%15 = OpConstant  %2  1.0
+%5 = OpFunction  %2  None %6
+%3 = OpFunctionParameter  %4
+%7 = OpLabel
+%8 = OpLoad  %2  %3
+OpReturnValue %8
+OpFunctionEnd
+%11 = OpFunction  %10  None %12
+%13 = OpLabel
+%9 = OpVariable  %4  Function
+%14 = OpFunctionCall  %2  %5 %15
+OpStore %9 %14
+OpReturn
+OpFunctionEnd