From 7e9a1634c8e6e9cab1f952e21a1d2a55acc2de40 Mon Sep 17 00:00:00 2001
From: Ardis Lu <ardisglu@gmail.com>
Date: Sun, 26 Oct 2025 23:08:16 -0700
Subject: [PATCH] Add explicit types

---
 examples/ex1_1.js | 2 ++
 examples/ex1_2.js | 2 ++
 examples/ex1_5.js | 3 +++
 examples/ex1_7.js | 2 ++
 examples/ex1_9.js | 3 +++
 examples/ex4_2.js | 2 ++
 6 files changed, 14 insertions(+)

diff --git a/examples/ex1_1.js b/examples/ex1_1.js
index 11389cd..e376ace 100644
--- a/examples/ex1_1.js
+++ b/examples/ex1_1.js
@@ -9,7 +9,9 @@
 // - The expected output of the transformation function is another array representing 1 row of the output CSV.
 
 import { CSVReader, CSVTransformer, CSVWriter } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 
+/** @type {TransformationFunction} */
 function timesTwo(row) {
   return [Number(row[0]) * 2, Number(row[1]) * 2];
 }
diff --git a/examples/ex1_2.js b/examples/ex1_2.js
index 68ac864..13b8f51 100644
--- a/examples/ex1_2.js
+++ b/examples/ex1_2.js
@@ -7,7 +7,9 @@
 // - Setting `handleHeaders` to an array is the simplest way to rename headers, delete headers, or add new headers.
 
 import { CSVReader, CSVTransformer, CSVWriter } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 
+/** @type {TransformationFunction} */
 function sum(row) {
   return [...row, Number(row[0]) + Number(row[1])];
 }
diff --git a/examples/ex1_5.js b/examples/ex1_5.js
index 0d49b52..4796d69 100644
--- a/examples/ex1_5.js
+++ b/examples/ex1_5.js
@@ -8,13 +8,16 @@
 // or other arbitrary logic is required to determine the output header names.
 
 import { CSVReader, CSVTransformer, CSVWriter } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 
 // It is useful to split the header transformation into a separate function because the logic for the header
 // is likely different from the rest of the CSV.
+/** @type {TransformationFunction} */
 function handleHeaders(headers) {
   return [...headers, 'min', 'max', 'mean']; // Duplicate input headers as the first headers in the output
 }
 
+/** @type {TransformationFunction} */
 function calculate(row) {
   const numbers = row.map(Number);
   const min = Math.min(...numbers);
diff --git a/examples/ex1_7.js b/examples/ex1_7.js
index abfadd3..1ba78fb 100644
--- a/examples/ex1_7.js
+++ b/examples/ex1_7.js
@@ -7,8 +7,10 @@
 // Aborting throws an error, so you must also add a `.catch()` to handle the abort.
 
 import { CSVReader, CSVTransformer, CSVWriter } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 
 const controller = new AbortController();
+/** @type {TransformationFunction} */
 function identityWithAbort(row) {
   if (row[0] === 'abort') { // Arbitrary logic for aborting the transformation
     controller.abort();
diff --git a/examples/ex1_9.js b/examples/ex1_9.js
index e4c10a9..ed41521 100644
--- a/examples/ex1_9.js
+++ b/examples/ex1_9.js
@@ -9,12 +9,15 @@
 
 import { createWriteStream } from 'node:fs';
 import { Writable } from 'node:stream';
+import { DecompressionStream, TextDecoderStream, CompressionStream } from 'node:stream/web';
 
 import { CSVReader, CSVTransformer, CSVWriter } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 
 import { createFileStream } from '../src/core.js';
 import { setGzipOSByteToUnknown } from '../test/utils.js';
 
+/** @type {TransformationFunction} */
 function timesTwo(row) {
   return [Number(row[0]) * 2, Number(row[1]) * 2];
 }
diff --git a/examples/ex4_2.js b/examples/ex4_2.js
index 7764201..707a1b7 100644
--- a/examples/ex4_2.js
+++ b/examples/ex4_2.js
@@ -5,6 +5,7 @@
 // common CSV mangling by spreadsheet programs.
 
 import { CSVReader, CSVWriter, CSVNormalizer, CSVDenormalizer, CSVTransformer } from '../src/index.js';
+/** @import { TransformationFunction } from '../src/index.js'; */
 /** @import { CSVNormalizerHeader } from '../src/normalization.js'; */
 
 // A minimal declaration to tell `CSVNormalizer` to trim empty rows and columns but otherwise don't touch the data
@@ -18,6 +19,7 @@ const headers = [
   'sparse3'
 ];
 
+/** @type {TransformationFunction} */
 function transform(row) {
   let c = 0
   for (const field of row) {
-- 
2.47.3