Index: frontend/node_modules/@rtsao/scc/LICENSE
===================================================================
--- frontend/node_modules/@rtsao/scc/LICENSE	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/LICENSE	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 Ryan Tsao
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
Index: frontend/node_modules/@rtsao/scc/README.md
===================================================================
--- frontend/node_modules/@rtsao/scc/README.md	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/README.md	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,49 @@
+# `@rtsao/scc`
+
+Find strongly connected components of a directed graph using [Tarjan's algorithm](https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm).
+
+This algorithm efficiently yields both a topological order and list of any cycles.
+
+## Installation
+
+```
+yarn add @rtsao/scc
+```
+
+```
+npm install @rtsao/scc
+```
+
+## Usage
+
+```js
+const scc = require("@rtsao/scc");
+
+const digraph = new Map([
+  ["a", new Set(["c", "d"])],
+  ["b", new Set(["a"])],
+  ["c", new Set(["b"])],
+  ["d", new Set(["e"])],
+  ["e", new Set()]
+]);
+
+const components = scc(digraph);
+// [ Set { 'e' }, Set { 'd' }, Set { 'b', 'c', 'a' } ]
+```
+
+#### Illustration of example input digraph
+```
+┌───┐     ┌───┐
+│ d │ ◀── │ a │ ◀┐
+└───┘     └───┘  │
+  │         │    │
+  ▼         ▼    │
+┌───┐     ┌───┐  │
+│ e │     │ c │  │
+└───┘     └───┘  │
+            │    │
+            ▼    │
+          ┌───┐  │
+          │ b │ ─┘
+          └───┘
+```
Index: frontend/node_modules/@rtsao/scc/index.d.ts
===================================================================
--- frontend/node_modules/@rtsao/scc/index.d.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/index.d.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,1 @@
+export default function tarjan<T>(graph: Map<T, Set<T>>): Array<Set<T>>
Index: frontend/node_modules/@rtsao/scc/index.js
===================================================================
--- frontend/node_modules/@rtsao/scc/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,51 @@
+"use strict";
+
+module.exports = tarjan;
+
+// Adapted from https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm#The_algorithm_in_pseudocode
+
+function tarjan(graph) {
+  const indices = new Map();
+  const lowlinks = new Map();
+  const onStack = new Set();
+  const stack = [];
+  const scc = [];
+  let idx = 0;
+
+  function strongConnect(v) {
+    indices.set(v, idx);
+    lowlinks.set(v, idx);
+    idx++;
+    stack.push(v);
+    onStack.add(v);
+
+    const deps = graph.get(v);
+    for (const dep of deps) {
+      if (!indices.has(dep)) {
+        strongConnect(dep);
+        lowlinks.set(v, Math.min(lowlinks.get(v), lowlinks.get(dep)));
+      } else if (onStack.has(dep)) {
+        lowlinks.set(v, Math.min(lowlinks.get(v), indices.get(dep)));
+      }
+    }
+
+    if (lowlinks.get(v) === indices.get(v)) {
+      const vertices = new Set();
+      let w = null;
+      while (v !== w) {
+        w = stack.pop();
+        onStack.delete(w);
+        vertices.add(w);
+      }
+      scc.push(vertices);
+    }
+  }
+
+  for (const v of graph.keys()) {
+    if (!indices.has(v)) {
+      strongConnect(v);
+    }
+  }
+
+  return scc;
+}
Index: frontend/node_modules/@rtsao/scc/index.js.flow
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--- frontend/node_modules/@rtsao/scc/index.js.flow	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/index.js.flow	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,5 @@
+// @flow
+
+declare function tarjan<T>(graph: Map<T, Set<T>>): Array<Set<T>>;
+
+declare module.exports: typeof tarjan;
Index: frontend/node_modules/@rtsao/scc/package.json
===================================================================
--- frontend/node_modules/@rtsao/scc/package.json	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/@rtsao/scc/package.json	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,7 @@
+{
+  "name": "@rtsao/scc",
+  "version": "1.1.0",
+  "repository": "rtsao/scc",
+  "main": "index.js",
+  "license": "MIT"
+}