4 files changed, 222 insertions, 0 deletions
diff --git a/tests/language-feature/if-let/if-let-1.slang b/tests/language-feature/if-let/if-let-1.slang
new file mode 100644
index 000000000..c197f26ea
--- /dev/null
+++ b/tests/language-feature/if-let/if-let-1.slang
@@ -0,0 +1,89 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -cpu -compute -shaderobj
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -cuda -compute -shaderobj
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=CHECK):-vk -compute -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+
+interface IFoo
+{
+    int foo(int a);
+}
+
+struct MyImpl1 : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+struct MyImpl2 : IFoo
+{
+    int foo(int a) { return a + 5; }
+}
+
+int test(IFoo foo, int idx)
+{
+    int val = 0;
+    if (let a = foo as MyImpl1)
+    {
+        val = a.foo(idx);
+    }
+    else if (let a = foo as MyImpl2)
+    {
+        val = a.foo(idx);
+    }
+    return (val);
+}
+
+int test1<T>(T t)
+{
+    if (let a = t as uint)
+    {
+        return 1;
+    }
+    else if(let a = t as float)
+    {
+        return 2;
+    }
+    else if (let a = t as double)
+    {
+        return 3;
+    }
+    else if (let a = t as int)
+    {
+        return 4;
+    }
+    else if (let a = t as uint64_t)
+    {
+        return 5;
+    }
+    else
+    {
+        return 6;
+    }
+}
+
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    MyImpl1 impl1;
+    MyImpl2 impl2;
+    // CHECK: 1
+    // CHECK: 7
+    outputBuffer[0] = test(impl1, 1);
+    outputBuffer[1] = test(impl2, 2);
+
+    // CHECK: 1
+    outputBuffer[2] = test1(2U);
+    // CHECK: 2
+    outputBuffer[3] = test1(2.0f);
+    // CHECK: 3
+    outputBuffer[4] = test1(2.0lf);
+    // CHECK: 4
+    outputBuffer[5] = test1(2);
+    // CHECK: 5
+    outputBuffer[6] = test1(2LLU);
+    // CHECK: 6
+    outputBuffer[7] = test1(impl1);
+}
diff --git a/tests/language-feature/if-let/if-let-diagnose-1.slang b/tests/language-feature/if-let/if-let-diagnose-1.slang
new file mode 100644
index 000000000..2322abb1a
--- /dev/null
+++ b/tests/language-feature/if-let/if-let-diagnose-1.slang
@@ -0,0 +1,53 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target hlsl -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target cuda -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target cpp -stage compute -entry computeMain
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+
+interface IFoo
+{
+    int foo(int a);
+}
+
+struct MyImpl : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+struct MyImpl1 : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+int test(IFoo foo, int idx)
+{
+    int val = 0;
+    if (let a = foo as MyImpl)
+    {
+        val = a.foo(idx);
+    }
+    // CHECK: error 30015: undefined identifier 'a'.
+    else if(a == none)
+    {
+        val = -1;
+    }
+    else
+    {
+        // CHECK: error 30015: undefined identifier 'a'.
+        if (a == none)
+        {
+            val = -1;
+        }
+    }
+    return (val);
+}
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    MyImpl1 impl;
+    outputBuffer[dispatchThreadID.x] = test(impl, dispatchThreadID.x);
+}
diff --git a/tests/language-feature/if-let/if-let-diagnose.slang b/tests/language-feature/if-let/if-let-diagnose.slang
new file mode 100644
index 000000000..4e9aa69c7
--- /dev/null
+++ b/tests/language-feature/if-let/if-let-diagnose.slang
@@ -0,0 +1,42 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target hlsl -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target cuda -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target cpp -stage compute -entry computeMain
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+
+interface IFoo
+{
+    int foo(int a);
+}
+
+struct MyImpl : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+struct MyImpl1 : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+int test(IFoo foo, int idx)
+{
+    int val = 0;
+    // CHECK: error 20002: syntax error.
+    if ((let a = foo as MyImpl))
+    {
+        val = a.foo(idx);
+    }
+    return (val);
+}
+
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    MyImpl impl;
+    outputBuffer[dispatchThreadID.x] = test(impl, dispatchThreadID.x);
+}
diff --git a/tests/language-feature/if-let/if-let.slang b/tests/language-feature/if-let/if-let.slang
new file mode 100644
index 000000000..5bb31030f
--- /dev/null
+++ b/tests/language-feature/if-let/if-let.slang
@@ -0,0 +1,38 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -cpu -compute -shaderobj
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -cuda -compute -shaderobj
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=CHECK):-vk -compute -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+
+interface IFoo
+{
+    int foo(int a);
+}
+
+struct MyImpl : IFoo
+{
+    int foo(int a) { return a; }
+}
+
+int test(IFoo foo, int idx)
+{
+    int val = 0;
+    if (let a = foo as MyImpl)
+    {
+        val = a.foo(idx);
+    }
+    return (val);
+}
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    MyImpl impl;
+    // CHECK: 0
+    // CHECK: 1
+    // CHECK: 2
+    // CHECK: 3
+    outputBuffer[dispatchThreadID.x] = test(impl, dispatchThreadID.x);
+}