feat(codemode): rank whole-word path matches above substring matches in search (#50275)

packages/codemode/src/tool-runtime.ts

@@ -192,6 +192,8 @@ export type Prepared<R = never> = {
 
 export type SearchEntry = {
   readonly description: ToolDescription
+  /** The path split into words, so `zones` matches `get_zones` as a word rather than as a substring of `timezones`. */
+  readonly pathWords: ReadonlyArray<string>
   readonly searchText: string
 }
 
@@ -247,6 +249,7 @@ const makeSearchTool = (searchIndex: ReadonlyArray<SearchEntry>): Tool => ({
                   (total, forms) =>
                     total +
                     (forms.some((form) => path === form || path.endsWith(`.${form}`)) ? 20 : 0) +
+                    (forms.some((form) => entry.pathWords.includes(form)) ? 12 : 0) +
                     (forms.some((form) => path.includes(form)) ? 8 : 0) +
                     (forms.some((form) => description.includes(form)) ? 4 : 0) +
                     (forms.some((form) => entry.searchText.includes(form)) ? 2 : 0),
@@ -281,6 +284,7 @@ export const searchSignature = (() => {
 
 const toSearchEntry = <R>(visible: VisibleTool<R>): SearchEntry => ({
   description: describeTool(visible),
+  pathWords: tokenize(visible.path),
   searchText: [
     visible.path,
     visible.tool.description,

packages/codemode/test/codemode.test.ts

@@ -1039,6 +1039,32 @@ describe("CodeMode public contract", () => {
     }
   })
 
+  test("a query term that is a whole word of the path outranks a substring of it", async () => {
+    const simple = (description: string) =>
+      Tool.make({
+        description,
+        input: Schema.Struct({}),
+        output: Schema.String,
+        execute: () => Effect.succeed("ok"),
+      })
+    const runtime = CodeMode.make({
+      tools: {
+        // Declared so that alphabetical order would put the substring match first.
+        cloudflare: { get_timezones: simple("List timezones"), get_zones: simple("List zones") },
+      },
+    })
+
+    const ranked = await Effect.runPromise(runtime.execute(`return search({ query: "zones" })`))
+    expect(ranked.ok).toBe(true)
+    if (ranked.ok) {
+      const value = ranked.value as { items: Array<{ path: string }> }
+      expect(value.items.map((item) => item.path)).toStrictEqual([
+        "tools.cloudflare.get_zones",
+        "tools.cloudflare.get_timezones",
+      ])
+    }
+  })
+
   test("a plural query term matches singular-only tool text", async () => {
     const simple = (description: string) =>
       Tool.make({