Update checked-in dependencies

node_modules/@rtsao/scc/index.js

@@ -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;
+}