Perf: drop stream transform for certain cases

Build/lib/fetch-text-by-line.ts

@@ -4,7 +4,7 @@ import readline from 'node:readline';
 import { TextLineStream } from 'foxts/text-line-stream';
 import type { ReadableStream } from 'node:stream/web';
 import { TextDecoderStream } from 'node:stream/web';
-import { processLine, ProcessLineStream } from './process-line';
+import { processLine as processLineFn, ProcessLineStream } from './process-line';
 import { $$fetch } from './fetch-retry';
 import type { UndiciResponseData } from './fetch-retry';
 import type { Response as UnidiciWebResponse } from 'undici';
@@ -44,11 +44,59 @@ export function fetchRemoteTextByLine(url: string, processLine = false): Promise
   return $$fetch(url).then(resp => createReadlineInterfaceFromResponse(resp, processLine));
 }
 
+export function splitTextIntoLines(
+  text: string,
+  processLine = false,
+  filter: ((line: string) => string | null) | null = null
+): string[] {
+  const lines: string[] = [];
+  const len = text.length;
+  let start = 0;
+
+  while (start <= len) {
+    let end = text.indexOf('\n', start);
+    const next = end === -1 ? len + 1 : end + 1;
+    if (end === -1) {
+      end = len;
+    }
+    if (end > start && text.charCodeAt(end - 1) === 13 /* \r */) {
+      end--;
+    }
+
+    if (end > start || (!processLine && start < len)) {
+      let line: string | null = text.slice(start, end);
+      if (filter) {
+        line = filter(line);
+      }
+      if (line !== null && processLine) {
+        line = processLineFn(line);
+      }
+      if (line !== null) {
+        lines.push(line);
+      }
+    }
+
+    start = next;
+  }
+
+  return lines;
+}
+
+/**
+ * Download a text asset and return its lines. The body is buffered and split
+ * synchronously -- see {@link splitTextIntoLines} for why that beats streaming
+ * when the result is an array anyway.
+ */
+export async function fetchRemoteTextLines(url: string, processLine = false): Promise<string[]> {
+  const resp = await $$fetch(url);
+  return splitTextIntoLines(await resp.text(), processLine);
+}
+
 export async function readFileIntoProcessedArray(file: string /* | FileHandle */) {
   const results = [];
   let processed: string | null = '';
   for await (const line of readFileByLine(file)) {
-    processed = processLine(line);
+    processed = processLineFn(line);
     if (processed) {
       results.push(processed);
     }