diff --git a/packages/transform-io/typescript/test/node/hdf5-test.js b/packages/transform-io/typescript/test/node/hdf5-test.js
index d4945d180..3fbeb942c 100644
--- a/packages/transform-io/typescript/test/node/hdf5-test.js
+++ b/packages/transform-io/typescript/test/node/hdf5-test.js
@@ -1,11 +1,22 @@
 import test from "ava";
 import path from "path";
 
-import { hdf5ReadTransformNode } from "../../dist/index-node.js";
+import {
+  hdf5ReadTransformNode,
+  hdf5WriteTransformNode,
+} from "../../dist/index-node.js";
 
-import { testInputPath, verifyTestLinearTransform } from "./common.js";
+import {
+  testInputPath,
+  testOutputPath,
+  verifyTestLinearTransform,
+} from "./common.js";
 
 const testInputFilePath = path.join(testInputPath, "LinearTransform.h5");
+const testOutputFilePath = path.join(
+  testOutputPath,
+  "hdf5-test-write-LinearTransform.h5"
+);
 
 test("Test reading a HDF5 file", async (t) => {
   const { couldRead, transform } = await hdf5ReadTransformNode(
@@ -14,3 +25,21 @@ test("Test reading a HDF5 file", async (t) => {
   t.true(couldRead);
   verifyTestLinearTransform(t, transform);
 });
+
+test("Test writing a HDF5 transform file", async (t) => {
+  const { couldRead, transform } = await hdf5ReadTransformNode(
+    testInputFilePath
+  );
+  t.true(couldRead);
+
+  const { couldWrite } = await hdf5WriteTransformNode(
+    transform,
+    testOutputFilePath
+  );
+  t.true(couldWrite);
+
+  const { couldRead: couldReadBack, transform: transformBack } =
+    await hdf5ReadTransformNode(testInputFilePath);
+  t.true(couldReadBack);
+  verifyTestLinearTransform(t, transformBack);
+});
diff --git a/packages/transform-io/typescript/test/node/mat-test.js b/packages/transform-io/typescript/test/node/mat-test.js
index 105f4082d..9ddd9a45a 100644
--- a/packages/transform-io/typescript/test/node/mat-test.js
+++ b/packages/transform-io/typescript/test/node/mat-test.js
@@ -1,11 +1,22 @@
 import test from "ava";
 import path from "path";
 
-import { matReadTransformNode } from "../../dist/index-node.js";
+import {
+  matReadTransformNode,
+  matWriteTransformNode,
+} from "../../dist/index-node.js";
 
-import { testInputPath, verifyTestLinearTransform } from "./common.js";
+import {
+  testInputPath,
+  testOutputPath,
+  verifyTestLinearTransform,
+} from "./common.js";
 
 const testInputFilePath = path.join(testInputPath, "LinearTransform.mat");
+const testOutputFilePath = path.join(
+  testOutputPath,
+  "mat-test-write-LinearTransform.mat"
+);
 
 test("Test reading a .mat file", async (t) => {
   const { couldRead, transform } = await matReadTransformNode(
@@ -14,3 +25,21 @@ test("Test reading a .mat file", async (t) => {
   t.true(couldRead);
   verifyTestLinearTransform(t, transform);
 });
+
+test("Test writing .mat transform file", async (t) => {
+  const { couldRead, transform } = await matReadTransformNode(
+    testInputFilePath
+  );
+  t.true(couldRead);
+
+  const { couldWrite } = await matWriteTransformNode(
+    transform,
+    testOutputFilePath
+  );
+  t.true(couldWrite);
+
+  const { couldRead: couldReadBack, transform: transformBack } =
+    await matReadTransformNode(testInputFilePath);
+  t.true(couldReadBack);
+  verifyTestLinearTransform(t, transformBack);
+});
diff --git a/packages/transform-io/typescript/test/node/txt-test.js b/packages/transform-io/typescript/test/node/txt-test.js
index 7f2eab445..7c8257f97 100644
--- a/packages/transform-io/typescript/test/node/txt-test.js
+++ b/packages/transform-io/typescript/test/node/txt-test.js
@@ -1,16 +1,45 @@
 import test from "ava";
 import path from "path";
 
-import { txtReadTransformNode } from "../../dist/index-node.js";
+import {
+  txtReadTransformNode,
+  txtWriteTransformNode,
+} from "../../dist/index-node.js";
 
-import { testInputPath, verifyTestLinearTransform } from "./common.js";
+import {
+  testInputPath,
+  testOutputPath,
+  verifyTestLinearTransform,
+} from "./common.js";
 
 const testInputFilePath = path.join(testInputPath, "LinearTransform.txt");
+const testOutputFilePath = path.join(
+  testOutputPath,
+  "txt-test-write-LinearTransform.txt"
+);
 
-test("Test reading a Insight Legacy TXT transform file", async (t) => {
+test("Test reading an Insight Legacy TXT transform file", async (t) => {
   const { couldRead, transform } = await txtReadTransformNode(
     testInputFilePath
   );
   t.true(couldRead);
   verifyTestLinearTransform(t, transform);
 });
+
+test("Test writing an Insight Legacy TXT transform file", async (t) => {
+  const { couldRead, transform } = await txtReadTransformNode(
+    testInputFilePath
+  );
+  t.true(couldRead);
+
+  const { couldWrite } = await txtWriteTransformNode(
+    transform,
+    testOutputFilePath
+  );
+  t.true(couldWrite);
+
+  const { couldRead: couldReadBack, transform: transformBack } =
+    await txtReadTransformNode(testInputFilePath);
+  t.true(couldReadBack);
+  verifyTestLinearTransform(t, transformBack);
+});