minor cleanup of rendering fns

src/render.ts

@@ -1,45 +1,42 @@
 
-import type { RenderItemsFn } from './types.js';
+import type { Item, RenderItemsFn } from './types.js';
 
 import { stringify } from 'csv-stringify/sync';
 import columnify from 'columnify';
 
+type Row = Record<string, string>;
+
+const toRow = (item: Item, show_tags: string[]): Row => {
+  return show_tags.reduce((acc, tag) => {
+    acc[tag] = item.tags[tag];
+    return acc;
+  }, Object.create(null));
+};
+
+const toRows = (items: Item[], show_tags: string[]): Row[] => {
+  return items.map(item => toRow(item, show_tags));
+};
+
 export const renderTabular: RenderItemsFn = (items, show_tags) => {
-  const data = items.map((task) => { 
-    const row: Record<string, any> = {};
-    show_tags.forEach((tag) => {
-      row[tag] = task.tags[tag] ?? '';
-    });
-    return row;
-  });
-  data.unshift(show_tags.reduce((acc, col) => { 
+  const rows = toRows(items, show_tags);
+  rows.unshift(show_tags.reduce((acc, col) => { 
     acc[col] = ''.padStart(col.length, '-');
     return acc;
   }, {} as any));
-  const opts: columnify.GlobalOptions = { 
+  return columnify(rows, { 
     columns: show_tags, 
     columnSplitter: ' | ',
-    headingTransform: data => data,
-  };
-  return columnify(data, opts);
+    headingTransform: heading => heading,
+  });
 };
 
 export const renderCSV: RenderItemsFn = (items, show_tags) => {
-  return stringify(items.map((task) => { 
-    const row: Record<string, any> = {};
-    show_tags.forEach((tag) => {
-      row[tag] = task.tags[tag] ?? '';
-    });
-    return row;
-  }), { columns: show_tags, header: true });
+  return stringify(
+    toRows(items, show_tags), 
+    { columns: show_tags, header: true },
+  );
 };
 
 export const renderJSON: RenderItemsFn = (items, show_tags) => {
-  return JSON.stringify(items.map((task) => {
-    const entry: Record<string, any> = {};
-    show_tags.forEach((tag) => {
-      entry[tag] = task.tags[tag];
-    });
-    return entry;
-  }));
+  return JSON.stringify(toRows(items, show_tags));
 };