build: upgrade to webpack 5

1 files changed, 45 insertions, 0 deletions

diff --git a/src/misc/createResource.ts b/src/misc/createResource.ts
new file mode 100644
index 0000000..9ff57e5
--- /dev/null
+++ b/src/misc/createResource.ts
@@ -0,0 +1,45 @@
+// from https://gist.github.com/ryanflorence/e10cc9dbc0e259759ec942ba82e5b57c
+export function createResource(getPromise: (key: string) => Promise<any>) {
+  let cache = {};
+  const inflight = {};
+  const errors = {};
+
+  function load(key = 'default') {
+    inflight[key] = getPromise(key)
+      .then((val) => {
+        delete inflight[key];
+        cache[key] = val;
+      })
+      .catch((error) => {
+        errors[key] = error;
+      });
+    return inflight[key];
+  }
+
+  function preload(key = 'default') {
+    if (cache[key] !== undefined || inflight[key]) return;
+    load(key);
+  }
+
+  function read(key = 'default') {
+    if (cache[key] !== undefined) {
+      return cache[key];
+    } else if (errors[key]) {
+      throw errors[key];
+    } else if (inflight[key]) {
+      throw inflight[key];
+    } else {
+      throw load(key);
+    }
+  }
+
+  function clear(key: 'default') {
+    if (key) {
+      delete cache[key];
+    } else {
+      cache = {};
+    }
+  }
+
+  return { preload, read, clear };
+}