feat: util/func isTruthy

Author: EqualMa

src/rollup/gen-pkg.ts

@@ -1,6 +1,7 @@
 import { InputOption } from "rollup";
 import { deepTrimStartDir, joinPath, trimStartDir } from "../util/path";
 import { posix as pp } from "path";
+import { isTruthy } from "../util/func";
 
 export interface GetEntryPointsFormatOptions {
   baseDir?: string;
@@ -191,7 +192,7 @@ function flatIndexEntryPoints<T>(ep: Record<string, T>): [string, T][] {
         e.endsWith("/index") ? [`./${e.slice(0, e.length - 6)}`, file] : null,
       ];
 
-      return entries.filter(<T>(v: T): v is NonNullable<T> => !!v);
+      return entries.filter(isTruthy);
     })
     .flat(1);
 }

src/rollup/options.ts

@@ -59,7 +59,7 @@ export async function rollupOptions({
     bundleOptions && rollupBundle(bundleOptions),
     nodeOptions && rollupNode(nodeOptions),
     dtsOptions && rollupDts(dtsOptions),
-  ].filter((v): v is Promise<RollupOptions> => !!v);
+  ].filter(isTruthy);
 
   return Promise.all(options);
 }

src/util/func.ts

@@ -0,0 +1,5 @@
+export type FalsyValueExceptNaN = false | 0 | 0n | "" | null | undefined;
+
+export const isTruthy = Boolean as unknown as <T>(
+  v: T,
+) => v is Exclude<T, FalsyValueExceptNaN>;