✔️ test: Make tests pass.

Author: make-github-pseudonymous-again

package.json

@@ -52,7 +52,10 @@
     "test": "ava",
     "travis": "npm run lint && npm run cover"
   },
-  "dependencies": {},
+  "dependencies": {
+    "@aureooms/js-pairing-heap": "^1.0.0",
+    "@aureooms/js-pairs": "^0.0.0"
+  },
   "devDependencies": {
     "@aureooms/js-compare": "^1.4.8",
     "@babel/cli": "7.13.10",

src/kahn.js

@@ -0,0 +1,26 @@
+/**
+ * Kahn's algorithm.
+ *
+ * See https://en.wikipedia.org/wiki/Topological_sorting#CITEREFKahn1962
+ *
+ * @param {any} queue
+ * @param {any} graph
+ * @returns {Iterable<any>} The vertices in topological order.
+ */
+export default function* kahn(queue, graph) {
+	while (true) {
+		const u = queue.pop();
+		if (u === undefined) break;
+		yield u;
+		for (const v of graph.rightOf(u)) {
+			graph.delete([u, v]);
+			if (graph.leftOf(v).next().done) {
+				queue.push(v);
+			}
+		}
+	}
+
+	if (graph.size > 0) {
+		throw new Error('kahn: graph has at least one cycle');
+	}
+}

src/sorted.js

@@ -1,3 +1,8 @@
+import Heap from '@aureooms/js-pairing-heap';
+import {EfficientlyInvertiblePairs as Pairs} from '@aureooms/js-pairs';
+
+import kahn from './kahn.js';
+
 /**
  * Sort the vertices topologically breaking ties according to a given function.
  *
@@ -6,11 +11,13 @@
  * @returns {Iterable<any>} The vertices sorted in topological order.
  */
 export default function sorted(edges, breakTies = (_a, _b) => -1) {
-	const vertices = new Set();
-	for (const [u, v] of edges) {
-		vertices.add(u);
-		vertices.add(v);
-	}
+	const graph = Pairs.from(edges);
+
+	const queue = new Heap(breakTies);
+	const freeVertices = new Set();
+	for (const [u] of graph) freeVertices.add(u);
+	for (const [, v] of graph) freeVertices.delete(v);
+	for (const u of freeVertices) queue.push(u);
 
-	return [...vertices].sort(breakTies)[Symbol.iterator]();
+	return kahn(queue, graph);
 }

yarn.lock

@@ -2,11 +2,44 @@
 # yarn lockfile v1
 
 
+"@aureooms/js-collections-deque@^4.0.1":
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-collections-deque/-/js-collections-deque-4.0.1.tgz#bd8b827cdb597d061525c380dd704e338c77bd5f"
+  integrity sha512-dktRVLyep0sUKpqgtG/JseA232KMdlu9t9ePq2wHcng1dZ3+63qW2C+FlKXBktrT1dU92DDxIL6PqnV97kHA1Q==
+  dependencies:
+    "@aureooms/js-error" "^4.0.1"
+
 "@aureooms/js-compare@^1.4.8":
   version "1.4.8"
   resolved "https://registry.yarnpkg.com/@aureooms/js-compare/-/js-compare-1.4.8.tgz#c6bff1091f4a2e211f449299572d9f195146fc59"
   integrity sha512-Z26PU6OmuhS7ZJsELTKImmipF7J+KCOyN70wBhhVIhmqUhXY6C3JpJHAev6wNBkC4ThlQt3zO6p/OmBFIq76Qg==
 
+"@aureooms/js-error@^4.0.1":
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-error/-/js-error-4.0.1.tgz#be2740b3f31a337e0828930c9b70d38113b4dd77"
+  integrity sha512-zsgs6wmnRsKljlusewYiBaFBM/hIJp43b7OwE9ybpLEL4wfXjGP17cJTTAY8gpzALVFwEA5/flxIK0I6gJJLHQ==
+
+"@aureooms/js-itertools@^4.1.0":
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-itertools/-/js-itertools-4.1.0.tgz#c731eaee7de0005c6ea41f2f87cca4bdb2d86ca1"
+  integrity sha512-P9TfwQPuXk5T5z6QMMfwLLyzh9QsEu4sGWcBk/P/waWgim/xqr+LDTOHVo7WU4QAty+/5CBX8DuW7MrPVfXt5A==
+  dependencies:
+    "@aureooms/js-collections-deque" "^4.0.1"
+    "@aureooms/js-error" "^4.0.1"
+
+"@aureooms/js-pairing-heap@^1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-pairing-heap/-/js-pairing-heap-1.0.0.tgz#76429704ae5db8fd2c81a60352b87dab88b3d6b6"
+  integrity sha512-lfaBSlUCIaxkYZXRwg7imCSeWS0AA8gFkV2CANaTuirB7hzLYdzPV8ePCw3MULZBdA2Ehq3CDGX2HxcqToZm7g==
+
+"@aureooms/js-pairs@^0.0.0":
+  version "0.0.0"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-pairs/-/js-pairs-0.0.0.tgz#a9d348c367511d4e70e166c73085ffc98c5fecf6"
+  integrity sha512-zsyLmTpXZ2cQmVMCU1FnUIwiaaFEhZ9FiotgjVjsJLFhBoU+wIxykUyIDZXozRszQLnk5sa8gWIrnQ3azjQCUA==
+  dependencies:
+    "@aureooms/js-error" "^4.0.1"
+    "@aureooms/js-itertools" "^4.1.0"
+
 "@babel/[email protected]":
   version "7.13.10"
   resolved "https://registry.yarnpkg.com/@babel/cli/-/cli-7.13.10.tgz#3a9254cbe806639c8ca4ebd49ebe54b4267b88c9"