diff --git a/.changeset/spicy-camels-compare.md b/.changeset/spicy-camels-compare.md
new file mode 100644
index 000000000..7f21dd4a1
--- /dev/null
+++ b/.changeset/spicy-camels-compare.md
@@ -0,0 +1,5 @@
+---
+"solid-js": patch
+---
+
+test: add tests to `splitProps` and `mergeProps`
diff --git a/packages/solid/test/component.spec.ts b/packages/solid/test/component.spec.ts
index 82d2763d9..9ddea5be6 100644
--- a/packages/solid/test/component.spec.ts
+++ b/packages/solid/test/component.spec.ts
@@ -62,17 +62,135 @@ describe("mergeProps", () => {
     expect(props.b).toBe(null);
     expect(props.c).toBe("j");
   });
+  it("skips undefined values", () => {
+    let bValue: number | undefined
+    const a = { value: 1 }
+    const b = { get value() { return bValue } }
+    const c = { get value() { return undefined } }
+    const props = mergeProps(a, b, c)
+    expect(props.value).toBe(1)
+    bValue = 2;
+    expect(props.value).toBe(2)
+  });
+  it("keeps references", () => {
+    const a = { value1: 1 }
+    const b = { value2: 2 }
+    const props = mergeProps(a, b)
+    a.value1 = b.value2 = 3
+    expect(props.value1).toBe(3)
+    expect(props.value2).toBe(3)
+  });
+  it("with getter keeps references", () => {
+    const a = { value1: 1 }
+    const b = { get value2() { return undefined } }
+    const props = mergeProps(a, b)
+    a.value1 = 3
+    expect(props.value1).toBe(3)
+  });
+  it("overrides enumerables", () => {
+    const a = Object.defineProperties({}, {
+      value1: {
+        enumerable: false,
+        value: 2
+      }
+    })
+    const props = mergeProps({}, a)
+    expect((props as any).value1).toBe(2)
+    expect(Object.getOwnPropertyDescriptor(props, 'value1')?.enumerable).toBeTruthy()
+    expect(Object.keys(props).join()).toBe("value1")
+  });
+  it("does not write the target", () => {
+    const props = { value1: 1 }
+    mergeProps(props, { value2: 2, get value3() { return 3 } })
+    expect(Object.keys(props).join("")).toBe('value1')
+  });
+  it("always returns a new reference", () => {
+    const props = {}
+    const newProps = mergeProps(props)
+    expect(props === newProps).toBeFalsy()
+  });
+  it("uses the source instances", () => {
+    const source1 = { get a() { return this } }
+    const source2 = { get b() { return this } }
+    const props = mergeProps(source1, source2)
+    expect(props.a === source1).toBeTruthy()
+    expect(props.b === source2).toBeTruthy()
+  });
+  it("does not clone nested objects", () => {
+    const b = { value: 1 }
+    const props = mergeProps({ a: 1 }, { b })
+    b.value = 2
+    expect(props.b.value).toBe(2)
+  });
+  it("always returns getters", () => {
+    const props = mergeProps({ a: 1 }, { b: 2 })
+    const desc = Object.getOwnPropertyDescriptors(props)
+    expect(!!desc.a.get).toBeTruthy()
+    expect(!!desc.b.get).toBeTruthy()
+  });
+  it("always returns unwritables", () => {
+    const props = mergeProps({ a: 1 }, { b: 2 })
+    const desc = Object.getOwnPropertyDescriptors(props)
+    expect(!!desc.a.writable).toBeFalsy()
+    expect(!!desc.b.writable).toBeFalsy()
+  });
+  it("ignores undefined values", () => {
+    const props = mergeProps({ a: 1 }, { a: undefined })
+    expect(props.a).toBe(1)
+  });
+  it("handles null values", () => {
+    const props = mergeProps({ a: 1 }, { a: null })
+    expect(props.a).toBeNull()
+  });
+  it("contains null values", () => {
+    const props = mergeProps({ a: null, get b() { return null; } })
+    expect(props.a).toBeNull();
+    expect(props.b).toBeNull();
+  });
+  it("contains undefined values", () => {
+    const props = mergeProps({ a: undefined, get b() { return undefined; } })
+    expect(Object.keys(props).join()).toBe('a,b')
+    expect('a' in props).toBeTruthy()
+    expect('b' in props).toBeTruthy()
+    expect(props.a).toBeUndefined();
+    expect(props.b).toBeUndefined();
+  });
+  it("ignores falsy sources", () => {
+    const props = mergeProps(undefined, null, { value: 1 }, null, undefined)
+    expect(Object.keys(props).join()).toBe('value')
+  });
+  it("fails with non objects sources", () => {
+    expect(() => mergeProps({ value: 1 }, true)).toThrowError()
+    expect(() => mergeProps({ value: 1 }, 1)).toThrowError()
+  });
+  it("works with a array source", () => {
+    const props = mergeProps({ value: 1 }, [2])
+    expect(Object.keys(props).join()).toBe('0,length,value')
+    expect(props.value).toBe(1)
+    expect(props.length).toBe(1)
+    expect(props[0]).toBe(2)
+  });
+  it("is safe", () => {
+    mergeProps({}, JSON.parse('{ "__proto__": { "evil": true } }'))
+    expect(({} as any).evil).toBeUndefined()
+    mergeProps({}, JSON.parse('{ "prototype": { "evil": true } }'))
+    expect(({} as any).evil).toBeUndefined()
+    mergeProps({ value: 1 }, JSON.parse('{ "__proto__": { "evil": true } }'))
+    expect(({} as any).evil).toBeUndefined()
+    mergeProps({ value: 1 }, JSON.parse('{ "prototype": { "evil": true } }'))
+    expect(({} as any).evil).toBeUndefined()
+  });
 });
 
 describe("Set Default Props", () => {
   test("simple set", () => {
     let props: SimplePropTypes = {
-        get a() {
-          return "ji";
-        },
-        b: null,
-        c: "j"
+      get a() {
+        return "ji";
       },
+      b: null,
+      c: "j"
+    },
       defaults: SimplePropTypes = { a: "yy", b: "ggg", d: "DD" };
     props = mergeProps(defaults, props);
     expect(props.a).toBe("ji");
@@ -122,12 +240,12 @@ describe("Clone Store", () => {
 describe("Merge Signal", () => {
   test("simple set", () => {
     const [s, set] = createSignal<SimplePropTypes>({
-        get a() {
-          return "ji";
-        },
-        b: null,
-        c: "j"
-      }),
+      get a() {
+        return "ji";
+      },
+      b: null,
+      c: "j"
+    }),
       defaults: SimplePropTypes = { a: "yy", b: "ggg", d: "DD" };
     let props!: SimplePropTypes;
     const res: string[] = [];
@@ -176,6 +294,83 @@ describe("SplitProps Props", () => {
       expect(out).toBe("Yo Bob");
     });
   });
+  test("SplitProps result is inmutable", () => {
+    const inProps = { first: 1, second: 2 }
+    const [props, otherProps] = splitProps(inProps, ["first"]);
+    inProps.first = inProps.second = 3
+    expect(props.first).toBe(1)
+    expect(otherProps.second).toBe(2)
+  });
+  test("SplitProps clones the descriptor", () => {
+    let signalValue = 1
+    const desc = {
+      signal: {
+        enumerable: true,
+        get() {
+          return signalValue
+        }
+      },
+      static: {
+        configurable: true,
+        enumerable: false,
+        value: 2
+      }
+    }
+    const inProps = Object.defineProperties({}, desc) as { signal: number, value1: number }
+    const [props, otherProps] = splitProps(inProps, ["signal"]);
+
+    expect(props.signal).toBe(1)
+    signalValue++
+    expect(props.signal).toBe(2)
+
+    const signalDesc = Object.getOwnPropertyDescriptor(props, "signal")!
+    expect(signalDesc.get === desc.signal.get).toBeTruthy()
+    expect(signalDesc.set).toBeUndefined()
+    expect(signalDesc.enumerable).toBeTruthy()
+    expect(signalDesc.configurable).toBeFalsy()
+
+    const staticDesc = Object.getOwnPropertyDescriptor(otherProps, "static")!
+    expect(staticDesc.value).toBe(2)
+    expect(staticDesc.get).toBeUndefined()
+    expect(staticDesc.set).toBeUndefined()
+    expect(staticDesc.enumerable).toBeFalsy()
+    expect(staticDesc.configurable).toBeTruthy()
+
+  });
+  test("SplitProps with multiple keys", () => {
+    const inProps: {
+      id?: string,
+      color?: string,
+      margin?: number,
+      padding?: number,
+      variant?: string,
+      description?: string
+    } = {
+      id: "input",
+      color: "red",
+      margin: 3,
+      variant: "outlined",
+      description: "test",
+    }
+
+    const [styleProps, inputProps, otherProps] = splitProps(
+      inProps,
+      ["color", "margin", "padding"],
+      ["variant", "description"]
+    );
+
+    expect(styleProps.color).toBe("red")
+    expect(styleProps.margin).toBe(3)
+    expect(styleProps.padding).toBeUndefined()
+    expect(Object.keys(styleProps).length).toBe(2)
+
+    expect(inputProps.description).toBe("test")
+    expect(inputProps.variant).toBe("outlined")
+    expect(Object.keys(inputProps).length).toBe(2)
+
+    expect(otherProps.id).toBe("input")
+    expect(Object.keys(otherProps).length).toBe(1)
+  });
   test("Merge SplitProps", () => {
     let value: string | undefined = undefined;
     const [splittedProps] = splitProps({ color: "blue" } as { color: string; other?: string }, [