feat(errors): add outOfBounds(), ensureIndex()

thi-ng · Mar 13, 2021 · fb5ca0a · fb5ca0a
1 parent 24c8afb
commit fb5ca0a
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diff --git a/packages/errors/src/index.ts b/packages/errors/src/index.ts
@@ -2,4 +2,5 @@ export * from "./deferror";
 export * from "./illegal-arguments";
 export * from "./illegal-arity";
 export * from "./illegal-state";
+export * from "./out-of-bounds";
 export * from "./unsupported";
diff --git a/packages/errors/src/out-of-bounds.ts b/packages/errors/src/out-of-bounds.ts
@@ -0,0 +1,17 @@
+import { defError } from "./deferror";
+
+export const OutOfBoundsError = defError<any>(() => "index out of bounds");
+
+export const outOfBounds = (index: number): never => {
+    throw new OutOfBoundsError(index);
+};
+
+/**
+ * Throws an {@link OutOfBoundsError} if `index` outside the `[min..max)` range.
+ *
+ * @param index
+ * @param min
+ * @param max
+ */
+export const ensureIndex = (index: number, min: number, max: number) =>
+    (index < min || index >= max) && outOfBounds(index);