feat(base-formula): add dependency graph with topo and cycle detection

apps/server/src/core/base/formula/__tests__/graph.spec.ts

@@ -0,0 +1,54 @@
+import { BaseFormulaGraph } from "@docmost/base-formula/server";
+
+type Prop = { id: string; type: string; typeOptions: any };
+
+const mk = (defs: Array<[string, string[]] | [string]>): Prop[] =>
+  defs.map(([id, deps]) => ({
+    id,
+    type: deps ? "formula" : "number",
+    typeOptions: deps ? { dependencies: deps } : {},
+  }));
+
+describe("BaseFormulaGraph", () => {
+  it("returns dependents", () => {
+    const g = new BaseFormulaGraph(mk([
+      ["A"], ["B"], ["C", ["A", "B"]],
+    ]));
+    expect(g.dependents("A").sort()).toEqual(["C"]);
+    expect(g.dependents("B").sort()).toEqual(["C"]);
+    expect(g.dependents("X")).toEqual([]);
+  });
+
+  it("produces a topological order", () => {
+    const g = new BaseFormulaGraph(mk([
+      ["A"], ["B", ["A"]], ["C", ["B"]],
+    ]));
+    const order = g.evalOrder();
+    expect(order.indexOf("B")).toBeLessThan(order.indexOf("C"));
+  });
+
+  it("computes transitive affected formulas", () => {
+    const g = new BaseFormulaGraph(mk([
+      ["A"], ["B", ["A"]], ["C", ["B"]], ["D", ["A"]],
+    ]));
+    expect(g.affectedFormulas(["A"]).sort()).toEqual(["B", "C", "D"]);
+  });
+
+  it("detects a direct cycle", () => {
+    const props = mk([["A", ["B"]], ["B", ["A"]]]);
+    const g = new BaseFormulaGraph(props);
+    expect(g.detectCycle(props[0])).not.toBeNull();
+  });
+
+  it("detects a transitive cycle", () => {
+    const props = mk([["A", ["B"]], ["B", ["C"]], ["C", ["A"]]]);
+    const g = new BaseFormulaGraph(props);
+    expect(g.detectCycle(props[0])).not.toBeNull();
+  });
+
+  it("returns null when there is no cycle", () => {
+    const props = mk([["A"], ["B", ["A"]]]);
+    const g = new BaseFormulaGraph(props);
+    expect(g.detectCycle(props[1])).toBeNull();
+  });
+});