From: Ardis Lu <ardisglu@gmail.com>
Date: Sun, 27 Apr 2025 08:38:12 +0000 (-0700)
Subject: Refactor to unpack `options` into private properties
X-Git-Tag: v0.1.0~28
X-Git-Url: https://git.ardis.lu/?a=commitdiff_plain;h=72f25ea57d7a2c61e6d62ddf216138baaa22ca30;p=csvio

Refactor to unpack `options` into private properties

This change makes these properties consistent with other classes in this library. This change is also the simplest way to let the TypeScript language server understand that these properties are not null.
---

diff --git a/src/core.js b/src/core.js
index 4288790..333db9a 100644
--- a/src/core.js
+++ b/src/core.js
@@ -221,11 +221,17 @@ export class CSVReader extends ReadableStream {
  */
 export class CSVTransformer extends TransformStream {
   #fn;
-  #options;
   #concurrent = [];
   #batch = [];
   #firstChunk = true;
 
+  #handleHeaders;
+  #rawInput;
+  #rawOutput;
+  #onError;
+  #maxBatchSize;
+  #maxConcurrent;
+
   /**
    * @param {TransformationFunction} fn A function to process a row or rows of CSV data.
    * 
@@ -253,42 +259,39 @@ export class CSVTransformer extends TransformStream {
       flush: (controller) => this.#flush(controller),
     });
 
-    options.handleHeaders ??= false;
-    options.rawInput ??= false;
-    options.rawOutput ??= false;
-    options.onError ??= null;
-    options.maxBatchSize ??= 1;
-    options.maxConcurrent ??= 1;
+    this.#handleHeaders = options.handleHeaders ?? false;
+    this.#rawInput = options.rawInput ?? false;
+    this.#rawOutput = options.rawOutput ?? false;
+    this.#onError = options.onError ?? null;
+    this.#maxBatchSize = options.maxBatchSize ?? 1;
+    this.#maxConcurrent = options.maxConcurrent ?? 1;
 
     this.#fn = fn;
-    this.#options = options;
   }
 
   async #wrappedHeaderFn(row) {
-    const { onError, handleHeaders } = this.#options;
-    if (typeof handleHeaders === 'boolean') {
-      return handleHeaders ? await this.#wrappedFn(row) : row;
+    if (typeof this.#handleHeaders === 'boolean') {
+      return this.#handleHeaders ? await this.#wrappedFn(row) : row;
     }
-    if (Array.isArray(handleHeaders)) {
-      return handleHeaders;
+    if (Array.isArray(this.#handleHeaders)) {
+      return this.#handleHeaders;
     }
-    if (onError === null) { return await handleHeaders(row); }
-    try { return await handleHeaders(row); }
-    catch (e) { return await onError(row, e, handleHeaders); }
+    if (this.#onError === null) { return await this.#handleHeaders(row); }
+    try { return await this.#handleHeaders(row); }
+    catch (e) { return await this.#onError(row, e, this.#handleHeaders); }
   }
 
   async #wrappedFn(row) {
-    const { onError } = this.#options;
-    if (onError === null) { return await this.#fn(row); }
+    if (this.#onError === null) { return await this.#fn(row); }
     try { return await this.#fn(row); }
-    catch (e) { return await onError(row, e, this.#fn); }
+    catch (e) { return await this.#onError(row, e, this.#fn); }
   }
 
   #enqueueRow(row, controller) {
     if (row === null || row === undefined) { // Input row is consumed without emitting any output row
       return;
     }
-    else if (this.#options.rawOutput || typeof row === 'string') {
+    else if (this.#rawOutput || typeof row === 'string') {
       controller.enqueue(row);
     }
     else if (Array.isArray(row) && Array.isArray(row[0])) { // Multiple rows returned, enqueue each row separately
@@ -319,8 +322,7 @@ export class CSVTransformer extends TransformStream {
   }
 
   async #transform(chunk, controller) {
-    const { rawInput, maxBatchSize, maxConcurrent } = this.#options;
-    const row = rawInput ? chunk : JSON.parse(chunk);
+    const row = this.#rawInput ? chunk : JSON.parse(chunk);
 
     if (this.#firstChunk) {
       this.#firstChunk = false;
@@ -329,9 +331,9 @@ export class CSVTransformer extends TransformStream {
       return;
     }
 
-    if (maxBatchSize > 1) {
+    if (this.#maxBatchSize > 1) {
       this.#batch.push(row);
-      if (this.#batch.length === maxBatchSize) {
+      if (this.#batch.length === this.#maxBatchSize) {
         this.#concurrent.push(this.#wrappedFn(this.#batch));
         this.#batch.length = 0;
       }
@@ -340,7 +342,7 @@ export class CSVTransformer extends TransformStream {
       this.#concurrent.push(this.#wrappedFn(row));
     }
 
-    if (this.#concurrent.length === maxConcurrent) {
+    if (this.#concurrent.length === this.#maxConcurrent) {
       await this.#enqueueConcurrent(controller);
     }
   }