From: Lady <redacted>
Date: Tue, 27 Jun 2023 01:07:19 +0000 (-0700)
Subject: Add buffer getters and setters to binary.js
X-Git-Tag: 0.4.0^0
X-Git-Url: https://git.ladys.computer/Pisces/commitdiff_plain/d741139aff475642fe08978d39722b298cf96802?ds=inline;hp=db85724e827e633157ad1961e251ea162cc0a1be

Add buffer getters and setters to binary.js

These are rough equivalents to the `DataView` methods, but can be
called with any kind of array buffer or array buffer view. Internally,
they (weakly) remember a `DataView` instance for each buffer and use
that for accessing values (to ensure correct endianness behaviour).
---

diff --git a/binary.js b/binary.js
index 7105731..c149daf 100644
--- a/binary.js
+++ b/binary.js
@@ -79,9 +79,22 @@ const getViewByteLength =
 const getViewByteOffset =
   Object.getOwnPropertyDescriptor(viewPrototype, "byteOffset").get;
 const {
+  getBigInt64: viewGetInt64,
+  getBigUint64: viewGetUint64,
+  getFloat32: viewGetFloat32,
+  getFloat64: viewGetFloat64,
+  getInt8: viewGetInt8,
+  getInt16: viewGetInt16,
+  getInt32: viewGetInt32,
   getUint8: viewGetUint8,
+  getUint16: viewGetUint16,
+  getUint32: viewGetUint32,
+  setFloat32: viewSetFloat32,
+  setFloat64: viewSetFloat64,
   setUint8: viewSetUint8,
   setUint16: viewSetUint16,
+  setUint32: viewSetUint32,
+  setBigUint64: viewSetUint64,
 } = viewPrototype;
 
 /**
@@ -682,6 +695,437 @@ export const filenameSafeBase64Binary = ($, ...$s) =>
 export const filenameSafeBase64String = ($, ...$s) =>
   encodeBase64(bufferFromArgs($, $s), true);
 
+export const {
+  /**
+   * Returns the signed 8‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getInt8`, but works on all array
+   * buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get8BitSignedIntegralItem,
+
+  /**
+   * Returns the unsigned 8‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getUint8`, but works on all array
+   * buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get8BitUnsignedIntegralItem,
+
+  /**
+   * Returns the signed 16‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getInt16`, but works on all array
+   * buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get16BitSignedIntegralItem,
+
+  /**
+   * Returns the unsigned 16‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getUint16`, but works on all
+   * array buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get16BitUnsignedIntegralItem,
+
+  /**
+   * Returns the 32‐bit floating point value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getFloat32`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get32BitFloatingPointItem,
+
+  /**
+   * Returns the signed 32‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getInt32`, but works on all array
+   * buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get32BitSignedIntegralItem,
+
+  /**
+   * Returns the unsigned 32‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getUint32`, but works on all
+   * array buffers and array buffer views and returns a big·int.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get32BitUnsignedIntegralItem,
+
+  /**
+   * Returns the 64‐bit floating point value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getFloat64`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get64BitFloatingPointItem,
+
+  /**
+   * Returns the signed 64‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getBigInt64`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get64BitSignedIntegralItem,
+
+  /**
+   * Returns the unsigned 64‐bit integral value in the provided array
+   * buffer or array buffer view at the provided byte offset.
+   *
+   * ※ The retrieved value will be big·endian unless a third argument
+   * is specified and truthy.
+   *
+   * ※ This is similar to `DataView::getBigUint64`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  get64BitUnsignedIntegralItem,
+
+  /**
+   * Sets the 8‐bit integral value in the provided array buffer or
+   * array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setInt8`, but works on all array
+   * buffers and array buffer views and accepts both numeric and
+   * big·int values.
+   *
+   * ※ It doesn’t matter whether the provided value is signed or
+   * unsigned, as the algorithm will cast one to the other.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  set8BitIntegralItem,
+
+  /**
+   * Sets the 16‐bit integral value in the provided array buffer or
+   * array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setInt16`, but works on all array
+   * buffers and array buffer views and accepts both numeric and
+   * big·int values.
+   *
+   * ※ It doesn’t matter whether the provided value is signed or
+   * unsigned, as the algorithm will cast one to the other.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  set16BitIntegralItem,
+
+  /**
+   * Sets the 32‐bit floating point value in the provided array buffer
+   * or array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setFloat32`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  set32BitFloatingPointItem,
+
+  /**
+   * Sets the 32‐bit integral value in the provided array buffer or
+   * array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setInt32`, but works on all array
+   * buffers and array buffer views and accepts both numeric and
+   * big·int values.
+   *
+   * ※ It doesn’t matter whether the provided value is signed or
+   * unsigned, as the algorithm will cast one to the other.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  set32BitIntegralItem,
+
+  /**
+   * Sets the 64‐bit floating point value in the provided array buffer
+   * or array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setFloat64`, but works on all
+   * array buffers and array buffer views.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array.
+   */
+  set64BitFloatingPointItem,
+
+  /**
+   * Sets the 64‐bit integral value in the provided array buffer or
+   * array buffer view at the provided byte offset to the provided
+   * value.
+   *
+   * ※ The value will be set as big·endian unless a fourth argument is
+   * specified and truthy.
+   *
+   * ※ This is similar to `DataView::setInt32`, but works on all array
+   * buffers and array buffer views.
+   *
+   * ※ It doesn’t matter whether the provided value is signed or
+   * unsigned, as the algorithm will cast one to the other.
+   *
+   * ☡ This function throws if the first argument is not an array
+   * buffer, data view, or typed array, or if the third argument is not
+   * a big·int.
+   */
+  set64BitIntegralItem,
+} = (() => {
+  const makeBigInt = BigInt;
+  const { asUintN } = BigInt;
+  const makeNumber = Number;
+
+  const viewMap = new WeakMap();
+  const view = ($) => {
+    const buffer = toArrayBuffer($);
+    if (viewMap.has(buffer)) {
+      // A view has already been allocated for this buffer; use it.
+      return viewMap.get(buffer);
+    } else {
+      // No view has been created for this buffer yet.
+      const result = new View(buffer);
+      viewMap.set(buffer, result);
+      return result;
+    }
+  };
+
+  return {
+    get8BitSignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetInt8, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get8BitUnsignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetUint8, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get16BitSignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetInt16, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get16BitUnsignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetUint16, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get32BitFloatingPointItem: ($, byteOffset, ...args) =>
+      call(viewGetFloat32, view($), [
+        getByteOffset($) + byteOffset,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    get32BitSignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetInt32, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get32BitUnsignedIntegralItem: ($, byteOffset, ...args) =>
+      makeBigInt(
+        call(viewGetUint32, view($), [
+          getByteOffset($) + byteOffset,
+          ...objectCreate(
+            argumentIterablePrototype,
+            { args: { value: args } },
+          ),
+        ]),
+      ),
+    get64BitFloatingPointItem: ($, byteOffset, ...args) =>
+      call(viewGetFloat64, view($), [
+        getByteOffset($) + byteOffset,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    get64BitSignedIntegralItem: ($, byteOffset, ...args) =>
+      call(viewGetInt64, view($), [
+        getByteOffset($) + byteOffset,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    get64BitUnsignedIntegralItem: ($, byteOffset, ...args) =>
+      call(viewGetUint64, view($), [
+        getByteOffset($) + byteOffset,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set8BitIntegralItem: ($, byteOffset, value, ...args) =>
+      call(viewSetUint8, view($), [
+        getByteOffset($) + byteOffset,
+        makeNumber(value),
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set16BitIntegralItem: ($, byteOffset, value, ...args) =>
+      call(viewSetUint16, view($), [
+        getByteOffset($) + byteOffset,
+        makeNumber(value),
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set32BitFloatingPointItem: ($, byteOffset, value, ...args) =>
+      call(viewSetFloat32, view($), [
+        getByteOffset($) + byteOffset,
+        value,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set32BitIntegralItem: ($, byteOffset, value, ...args) =>
+      call(viewSetUint32, view($), [
+        getByteOffset($) + byteOffset,
+        makeNumber(value),
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set64BitFloatingPointItem: ($, byteOffset, value, ...args) =>
+      call(viewSetFloat64, view($), [
+        getByteOffset($) + byteOffset,
+        value,
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+    set64BitIntegralItem: ($, byteOffset, value, ...args) =>
+      call(viewSetUint64, view($), [
+        getByteOffset($) + byteOffset,
+        asUintN(64, value),
+        ...objectCreate(
+          argumentIterablePrototype,
+          { args: { value: args } },
+        ),
+      ]),
+  };
+})();
+
 /**
  * Returns the byte length for the provided array buffer or array
  * buffer view.
diff --git a/binary.test.js b/binary.test.js
index c5c2600..98f441a 100644
--- a/binary.test.js
+++ b/binary.test.js
@@ -25,6 +25,16 @@ import {
   base64String,
   filenameSafeBase64Binary,
   filenameSafeBase64String,
+  get16BitSignedIntegralItem,
+  get16BitUnsignedIntegralItem,
+  get32BitFloatingPointItem,
+  get32BitSignedIntegralItem,
+  get32BitUnsignedIntegralItem,
+  get64BitFloatingPointItem,
+  get64BitSignedIntegralItem,
+  get64BitUnsignedIntegralItem,
+  get8BitSignedIntegralItem,
+  get8BitUnsignedIntegralItem,
   isArrayBuffer,
   isArrayBufferView,
   isBase16,
@@ -34,6 +44,12 @@ import {
   isSharedArrayBuffer,
   isTypedArray,
   isWRMGBase32,
+  set16BitIntegralItem,
+  set32BitFloatingPointItem,
+  set32BitIntegralItem,
+  set64BitFloatingPointItem,
+  set64BitIntegralItem,
+  set8BitIntegralItem,
   toArrayBuffer,
   wrmgBase32Binary,
   wrmgBase32String,
@@ -623,6 +639,191 @@ describe("filenameSafeBase64String", () => {
   });
 });
 
+describe("get8BitSignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from([0, -1, 0]).buffer;
+    assertStrictEquals(get8BitSignedIntegralItem(buffer, 1), -1n);
+    assertStrictEquals(
+      get8BitSignedIntegralItem(new DataView(buffer), 1),
+      -1n,
+    );
+    assertStrictEquals(
+      get8BitSignedIntegralItem(new Uint8Array(buffer), 1),
+      -1n,
+    );
+  });
+});
+
+describe("get8BitUnsignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from([0, -1, 0]).buffer;
+    assertStrictEquals(get8BitUnsignedIntegralItem(buffer, 1), 255n);
+    assertStrictEquals(
+      get8BitUnsignedIntegralItem(new DataView(buffer), 1),
+      255n,
+    );
+    assertStrictEquals(
+      get8BitUnsignedIntegralItem(new Int8Array(buffer), 1),
+      255n,
+    );
+  });
+});
+
+describe("get16BitSignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from([0, 0, -1, -1, 0, 0]).buffer;
+    assertStrictEquals(get16BitSignedIntegralItem(buffer, 2), -1n);
+    assertStrictEquals(
+      get16BitSignedIntegralItem(new DataView(buffer), 2),
+      -1n,
+    );
+    assertStrictEquals(
+      get16BitSignedIntegralItem(new Uint16Array(buffer), 2),
+      -1n,
+    );
+  });
+});
+
+describe("get16BitUnsignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from([0, 0, -1, -1, 0, 0]).buffer;
+    assertStrictEquals(
+      get16BitUnsignedIntegralItem(buffer, 2),
+      (1n << 16n) - 1n,
+    );
+    assertStrictEquals(
+      get16BitUnsignedIntegralItem(new DataView(buffer), 2),
+      (1n << 16n) - 1n,
+    );
+    assertStrictEquals(
+      get16BitUnsignedIntegralItem(new Int16Array(buffer), 2),
+      (1n << 16n) - 1n,
+    );
+  });
+});
+
+describe("get32BitFloatingPointItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = new ArrayBuffer(12);
+    const view = new DataView(buffer);
+    view.setFloat32(0, NaN);
+    view.setFloat32(4, -Infinity);
+    view.setFloat32(8, -0);
+    assertStrictEquals(get32BitFloatingPointItem(buffer, 0), NaN);
+    assertStrictEquals(
+      get32BitFloatingPointItem(buffer, 4),
+      -Infinity,
+    );
+    assertStrictEquals(get32BitFloatingPointItem(buffer, 8), -0);
+    assertStrictEquals(
+      get32BitFloatingPointItem(new DataView(buffer), 4),
+      -Infinity,
+    );
+    assertStrictEquals(
+      get32BitFloatingPointItem(new Uint32Array(buffer), 4),
+      -Infinity,
+    );
+  });
+});
+
+describe("get32BitSignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from(
+      [0, 0, 0, 0, -1, -1, -1, -1, 0, 0, 0, 0],
+    ).buffer;
+    assertStrictEquals(get32BitSignedIntegralItem(buffer, 4), -1n);
+    assertStrictEquals(
+      get32BitSignedIntegralItem(new DataView(buffer), 4),
+      -1n,
+    );
+    assertStrictEquals(
+      get32BitSignedIntegralItem(new Uint32Array(buffer), 4),
+      -1n,
+    );
+  });
+});
+
+describe("get32BitUnsignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from(
+      [0, 0, 0, 0, -1, -1, -1, -1, 0, 0, 0, 0],
+    ).buffer;
+    assertStrictEquals(
+      get32BitUnsignedIntegralItem(buffer, 4),
+      (1n << 32n) - 1n,
+    );
+    assertStrictEquals(
+      get32BitUnsignedIntegralItem(new DataView(buffer), 4),
+      (1n << 32n) - 1n,
+    );
+    assertStrictEquals(
+      get32BitUnsignedIntegralItem(new Int32Array(buffer), 4),
+      (1n << 32n) - 1n,
+    );
+  });
+});
+
+describe("get64BitFloatingPointItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = new ArrayBuffer(24);
+    const view = new DataView(buffer);
+    view.setFloat64(0, NaN);
+    view.setFloat64(8, -Infinity);
+    view.setFloat64(16, -0);
+    assertStrictEquals(get64BitFloatingPointItem(buffer, 0), NaN);
+    assertStrictEquals(
+      get64BitFloatingPointItem(buffer, 8),
+      -Infinity,
+    );
+    assertStrictEquals(get64BitFloatingPointItem(buffer, 16), -0);
+    assertStrictEquals(
+      get64BitFloatingPointItem(new DataView(buffer), 8),
+      -Infinity,
+    );
+    assertStrictEquals(
+      get64BitFloatingPointItem(new BigUint64Array(buffer), 8),
+      -Infinity,
+    );
+  });
+});
+
+describe("get64BitSignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from(
+      [0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1, -1, -1, -1, -1],
+    ).buffer;
+    assertStrictEquals(get64BitSignedIntegralItem(buffer, 8), -1n);
+    assertStrictEquals(
+      get64BitSignedIntegralItem(new DataView(buffer), 8),
+      -1n,
+    );
+    assertStrictEquals(
+      get64BitSignedIntegralItem(new BigUint64Array(buffer), 8),
+      -1n,
+    );
+  });
+});
+
+describe("get64BitUnsignedIntegralItem", () => {
+  it("[[Call]] gets the item", () => {
+    const buffer = Int8Array.from(
+      [0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1, -1, -1, -1, -1],
+    ).buffer;
+    assertStrictEquals(
+      get64BitUnsignedIntegralItem(buffer, 8),
+      (1n << 64n) - 1n,
+    );
+    assertStrictEquals(
+      get64BitUnsignedIntegralItem(new DataView(buffer), 8),
+      (1n << 64n) - 1n,
+    );
+    assertStrictEquals(
+      get64BitUnsignedIntegralItem(new BigInt64Array(buffer), 8),
+      (1n << 64n) - 1n,
+    );
+  });
+});
+
 describe("isArrayBuffer", () => {
   it("[[Call]] returns true for array buffers", () => {
     assertStrictEquals(
@@ -938,6 +1139,89 @@ describe("isWRMGBase32", () => {
   });
 });
 
+describe("set8BitIntegralItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(3);
+    set8BitIntegralItem(buffer, 1, -1n);
+    set8BitIntegralItem(buffer, 2, (1 << 8) - 1);
+    assertEquals(
+      new Int8Array(buffer),
+      Int8Array.from([0, -1, -1]),
+    );
+  });
+});
+
+describe("set16BitIntegralItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(6);
+    set16BitIntegralItem(buffer, 2, -1n);
+    set16BitIntegralItem(buffer, 4, (1 << 16) - 1);
+    assertEquals(
+      new Int8Array(buffer),
+      Int8Array.from([0, 0, -1, -1, -1, -1]),
+    );
+  });
+});
+
+describe("set32BitFloatingPointItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(12);
+    const expected = new ArrayBuffer(12);
+    const view = new DataView(expected);
+    view.setFloat32(0, NaN);
+    set32BitFloatingPointItem(buffer, 0, NaN);
+    view.setFloat32(4, -Infinity);
+    set32BitFloatingPointItem(buffer, 4, -Infinity);
+    view.setFloat32(8, -0);
+    set32BitFloatingPointItem(buffer, 8, -0);
+    assertEquals(
+      new Uint8Array(buffer),
+      new Uint8Array(expected),
+    );
+  });
+});
+
+describe("set32BitIntegralItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(12);
+    set32BitIntegralItem(buffer, 4, -1n);
+    set32BitIntegralItem(buffer, 8, -1 >>> 0);
+    assertEquals(
+      new Int8Array(buffer),
+      Int8Array.from([0, 0, 0, 0, -1, -1, -1, -1, -1, -1, -1, -1]),
+    );
+  });
+});
+
+describe("set64BitFloatingPointItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(24);
+    const expected = new ArrayBuffer(24);
+    const view = new DataView(expected);
+    view.setFloat64(0, NaN);
+    set64BitFloatingPointItem(buffer, 0, NaN);
+    view.setFloat64(4, -Infinity);
+    set64BitFloatingPointItem(buffer, 4, -Infinity);
+    view.setFloat64(8, -0);
+    set64BitFloatingPointItem(buffer, 8, -0);
+    assertEquals(
+      new Uint8Array(buffer),
+      new Uint8Array(expected),
+    );
+  });
+});
+
+describe("set64BitIntegralItem", () => {
+  it("[[Call]] sets the item", () => {
+    const buffer = new ArrayBuffer(12);
+    set64BitIntegralItem(buffer, 4, -1n);
+    assertEquals(
+      new Int8Array(buffer),
+      Int8Array.from([0, 0, 0, 0, -1, -1, -1, -1, -1, -1, -1, -1]),
+    );
+  });
+});
+
 describe("toArrayBuffer", () => {
   it("[[Call]] returns the argument for array buffers", () => {
     const buffer = new ArrayBuffer();