feat: add standalone glyphs data getter

src/standalone/glyphsData.ts

@@ -0,0 +1,73 @@
+import type {GlyphData, WebfontOptions} from "../types";
+import { createReadStream } from "fs";
+import fileSorter from "svgicons2svgfont/src/filesorter";
+import getMetadataService from "svgicons2svgfont/src/metadata";
+import pLimit from "p-limit";
+import xml2js from "xml2js";
+
+// eslint-disable-next-line no-unused-vars
+type GlyphsDataGetter = (files: Array<GlyphData["srcPath"]>, options: WebfontOptions) => unknown;
+
+export const getGlyphsData : GlyphsDataGetter = (files, options) => {
+  const metadataProvider =
+    options.metadataProvider ||
+    getMetadataService({
+      prependUnicode: options.prependUnicode,
+      startUnicode: options.startUnicode,
+    });
+
+  const xmlParser = new xml2js.Parser();
+  const throttle = pLimit(options.maxConcurrency);
+
+  return Promise.all(files.map((srcPath: GlyphData["srcPath"]) => throttle(() => new Promise((resolve, reject) => {
+    const glyph = createReadStream(srcPath);
+    let glyphContents = "";
+
+    // eslint-disable-next-line no-promise-executor-return
+    return glyph.
+      on("error", (glyphError) => reject(glyphError)).
+      on("data", (data) => {
+        glyphContents += data.toString();
+      }).
+      on("end", () => {
+      // Maybe bug in xml2js
+        if (glyphContents.length === 0) {
+          return reject(new Error(`Empty file ${srcPath}`));
+        }
+
+        return xmlParser.parseString(glyphContents, (error) => {
+          if (error) {
+            return reject(error);
+          }
+
+          const glyphData: GlyphData = {
+            contents: glyphContents,
+            srcPath,
+          };
+
+          return resolve(glyphData);
+        });
+      });
+  })))).then((glyphsData) => {
+
+    let sortedGlyphsData = glyphsData;
+
+    if (options.sort) {
+      const sortCallback = (fileA: GlyphData, fileB: GlyphData) => fileSorter(fileA.srcPath, fileB.srcPath);
+      sortedGlyphsData = glyphsData.sort(sortCallback);
+    }
+
+    return Promise.all(sortedGlyphsData.map((glyphData: GlyphData) => new Promise((resolve, reject) => {
+      metadataProvider(glyphData.srcPath, (error, metadata) => {
+        if (error) {
+          return reject(error);
+        }
+
+        metadata.unicode.push(metadata.name.replace(/-/gu, "_"));
+        glyphData.metadata = metadata;
+
+        return resolve(glyphData);
+      });
+    })));
+  });
+};