feat(spec): match idPrefix in the web runtime

The DOM has no package prefix, so the native rule reduces to [id^=]. Both
prefix kinds now go through the one key table, which drops the separate
descPrefix branch that string and object selectors each carried.

pkg/spec/src/types.ts

@@ -44,14 +44,27 @@ export interface KnownAttrSelectors {
   editable?: boolean;
 }
 
+/**
+ * Keys that name a matching rule rather than an attribute a driver reports.
+ * They belong to the selector surface only, which is why they are not part of
+ * `KnownAttrSelectors` (and so never appear in `RawAttrs`).
+ */
+export interface PrefixSelectors {
+  /** Identifier starts with this, after Android's "<package>:id/" if present. */
+  idPrefix?: string;
+  /** Accessibility description starts with this. */
+  descPrefix?: string;
+}
+
 /**
  * Object-form selector for `find` / `findAll`. Known attributes are typed
  * via `KnownAttrSelectors`; arbitrary string keys are still allowed for
  * raw driver attributes the typed surface doesn't yet cover.
  */
-export type AttrSelector = KnownAttrSelectors & {
+export type AttrSelector = KnownAttrSelectors &
+  PrefixSelectors & {
     [key: string]: string | boolean | undefined;
-};
+  };
 
 export type SelectorPath = readonly AttrSelector[];
 

pkg/spec/src/web-runtime.ts

@@ -85,6 +85,10 @@ function noopFormula(): unknown {
 const KNOWN_KEY_TO_CSS: Record<string, (value: string) => string> = {
   id: (v) => `[id="${cssEscape(v)}"]`,
   "resource-id": (v) => `[id="${cssEscape(v)}"]`,
+  // The native rule also accepts the local name after Android's "<package>:id/".
+  // The DOM has no such prefix, so a plain starts-with is the same rule here.
+  idPrefix: (v) => `[id^="${cssEscape(v)}"]`,
+  descPrefix: (v) => `[aria-label^="${cssEscape(v)}"]`,
   // The native table aliases testTag onto resource-id, which the host DOM walk
   // fills from el.id, so the native path already accepts a testTag emitted as
   // an id (what Compose Multiplatform does on web). Accept both here so the
@@ -131,7 +135,6 @@ function selectorFromObject(selector: Record<string, string | boolean | undefine
 } {
   const parts: string[] = [];
   let textValue: string | undefined;
-  let descPrefix: string | undefined;
   for (const key of Object.keys(selector)) {
     const raw = selector[key];
     if (raw === undefined) continue;
@@ -140,10 +143,6 @@ function selectorFromObject(selector: Record<string, string | boolean | undefine
       textValue = value;
       continue;
     }
-    if (key === "descPrefix") {
-      descPrefix = value;
-      continue;
-    }
     const builder = KNOWN_KEY_TO_CSS[key];
     if (builder) {
       parts.push(builder(value));
@@ -151,9 +150,6 @@ function selectorFromObject(selector: Record<string, string | boolean | undefine
       parts.push(`[${key}="${cssEscape(value)}"]`);
     }
   }
-  if (descPrefix !== undefined) {
-    parts.push(`[aria-label^="${cssEscape(descPrefix)}"]`);
-  }
   if (textValue !== undefined && parts.length === 0) {
     return {
       xpath: `//*[normalize-space(text())=${xpathStringLiteral(textValue)}]`,
@@ -182,9 +178,6 @@ function selectorFromString(selector: string): { css?: string; xpath?: string }
   if (kind === "text") {
     return { xpath: `//*[normalize-space(text())=${xpathStringLiteral(value)}]` };
   }
-  if (kind === "descPrefix") {
-    return { css: `[aria-label^="${cssEscape(value)}"]` };
-  }
   return selectorFromObject({ [kind]: value });
 }
 

pkg/spec/test/web-runtime.test.ts

@@ -327,6 +327,36 @@ test("selectorFromObject composes testTag with a second key", () => {
   });
 });
 
+// A list whose rows are named <role>_<record id> is only reachable by the role
+// half. internal/driver/chrome/translate.go builds the same CSS for the same
+// selector, and internal/hierarchy resolves it against the dump of this page.
+test("selectorFromString routes idPrefix to a starts-with id match", () => {
+  assert.deepEqual(selectorFromString("idPrefix:customer_row_"), {
+    css: `[id^="customer_row_"]`,
+  });
+});
+
+test("selectorFromObject routes idPrefix to a starts-with id match", () => {
+  assert.deepEqual(selectorFromObject({ idPrefix: "customer_row_" }), {
+    css: `[id^="customer_row_"]`,
+  });
+});
+
+test("selectorFromString and selectorFromObject agree on descPrefix", () => {
+  assert.deepEqual(selectorFromString("descPrefix:account:"), {
+    css: `[aria-label^="account\\:"]`,
+  });
+  assert.deepEqual(selectorFromObject({ descPrefix: "account:" }), {
+    css: `[aria-label^="account\\:"]`,
+  });
+});
+
+test("selectorFromObject composes idPrefix with a second key", () => {
+  assert.deepEqual(selectorFromObject({ idPrefix: "customer_row_", "aria-label": "first" }), {
+    css: `[id^="customer_row_"][aria-label="first"]`,
+  });
+});
+
 test("selectorFromObject falls back to a literal attribute for unknown keys", () => {
   assert.deepEqual(selectorFromObject({ "data-foo": "bar" }), {
     css: `[data-foo="bar"]`,