feat(plugin-system): plan 07 frontend plugin manager ui

1 files changed, 60 insertions, 0 deletions

diff --git a/src/features/plugins/logic/highlight.test.ts b/src/features/plugins/logic/highlight.test.ts
new file mode 100644
index 0000000..616f7ad
--- /dev/null
+++ b/src/features/plugins/logic/highlight.test.ts
@@ -0,0 +1,60 @@
+import { describe, expect, it } from "vitest";
+import { dependencyHighlightSets } from "./highlight";
+import { node } from "./test-fixtures";
+
+describe("dependencyHighlightSets", () => {
+  const nodes = [
+    node({ id: "lib", loaded: false, section: "discovered" }),
+    node({ id: "mid", dependsOn: ["lib"] }),
+    node({ id: "app", dependsOn: ["mid", "lib"] }),
+  ];
+
+  it("returns empty sets for no hover", () => {
+    const sets = dependencyHighlightSets(null, nodes);
+    expect(sets.deps.size).toBe(0);
+    expect(sets.dependents.size).toBe(0);
+  });
+
+  it("hovering an item highlights its DIRECT dependencies (one hop)", () => {
+    const sets = dependencyHighlightSets("app", nodes);
+    expect(sets.deps).toEqual(new Set(["mid", "lib"]));
+    expect(sets.dependents.size).toBe(0);
+  });
+
+  it("hovering a dependency highlights its dependents (both directions work)", () => {
+    const sets = dependencyHighlightSets("lib", nodes);
+    expect(sets.deps.size).toBe(0);
+    expect(sets.dependents).toEqual(new Set(["mid", "app"]));
+  });
+
+  it("hovering a middle node highlights BOTH directions", () => {
+    const sets = dependencyHighlightSets("mid", nodes);
+    expect(sets.deps).toEqual(new Set(["lib"]));
+    expect(sets.dependents).toEqual(new Set(["app"]));
+  });
+
+  it("is one hop — not the transitive closure", () => {
+    // app → mid → lib: hovering app highlights mid + lib (both direct deps),
+    // but hovering lib highlights only DIRECT dependents (mid, app) — already
+    // one hop. The one-hop rule shows in: a plugin two hops away via an
+    // unrelated chain is not highlighted.
+    const chain = [
+      node({ id: "a" }),
+      node({ id: "b", dependsOn: ["a"] }),
+      node({ id: "c", dependsOn: ["b"] }),
+    ];
+    expect(dependencyHighlightSets("c", chain).deps).toEqual(new Set(["b"]));
+  });
+
+  it("returns empty sets for an unknown hovered id", () => {
+    const sets = dependencyHighlightSets("ghost", nodes);
+    expect(sets.deps.size).toBe(0);
+    expect(sets.dependents.size).toBe(0);
+  });
+
+  it("works across sections (a loaded row highlights an unloaded dependency)", () => {
+    // `app` loaded, `lib` discovered: hovering app still highlights lib.
+    const sets = dependencyHighlightSets("app", nodes);
+    expect(sets.deps.has("lib")).toBe(true);
+  });
+});