diff --git a/tests/unit/components/Explore/ExploreV2/components/UniversalSearchResult.test.js b/tests/unit/components/Explore/ExploreV2/components/UniversalSearchResult.test.js
new file mode 100644
index 000000000..a3d8a8eca
--- /dev/null
+++ b/tests/unit/components/Explore/ExploreV2/components/UniversalSearchResult.test.js
@@ -0,0 +1,115 @@
+import { fireEvent, screen } from "@testing-library/react-native";
+import UniversalSearchResult
+  from "components/Explore/ExploreV2/components/UniversalSearchResult";
+import initI18next from "i18n/initI18next";
+import React from "react";
+import { renderComponent } from "tests/helpers/render";
+
+jest.mock( "sharedHooks/useCurrentUser", ( ) => ( {
+  __esModule: true,
+  default: jest.fn( ),
+} ) );
+const useCurrentUser = require( "sharedHooks/useCurrentUser" ).default;
+
+const TAXON_WITH_PHOTO = {
+  type: "taxon",
+  taxon: {
+    id: 12,
+    name: "Eumyias thalassinus",
+    preferred_common_name: "Verditer Flycatcher",
+    iconic_taxon_name: "Aves",
+    default_photo: { url: "https://example.com/t.jpg" },
+  },
+};
+
+const TAXON_WITHOUT_PHOTO = {
+  type: "taxon",
+  taxon: {
+    id: 13,
+    name: "Plantae",
+    iconic_taxon_name: "Plantae",
+  },
+};
+
+const USER_RESULT = {
+  type: "user",
+  user: {
+    id: 7,
+    login: "seth_msp",
+    icon_url: "https://example.com/u.jpg",
+    observations_count: 5,
+  },
+};
+
+const PROJECT_RESULT = {
+  type: "project",
+  project: {
+    id: 9,
+    title: "InverteFest",
+    project_type: "collection",
+    rule_preferences: [],
+    icon: "https://example.com/p.jpg",
+  },
+};
+
+beforeAll( async ( ) => {
+  await initI18next( );
+} );
+
+beforeEach( ( ) => {
+  useCurrentUser.mockReturnValue( {
+    prefers_common_names: true,
+    prefers_scientific_name_first: false,
+  } );
+} );
+
+describe( "UniversalSearchResult", ( ) => {
+  it( "renders a taxon result with its photo", ( ) => {
+    renderComponent(
+      <UniversalSearchResult result={TAXON_WITH_PHOTO} onPress={jest.fn( )} />,
+    );
+
+    expect( screen.getByTestId( "UniversalSearchResult.taxon.12" ) ).toBeTruthy( );
+    expect( screen.getByTestId( "UniversalSearchResult.taxonImage" ) ).toBeTruthy( );
+    expect( screen.getByText( "Verditer Flycatcher" ) ).toBeTruthy( );
+  } );
+
+  it( "falls back to the iconic taxon icon when a taxon has no photo", ( ) => {
+    renderComponent(
+      <UniversalSearchResult result={TAXON_WITHOUT_PHOTO} onPress={jest.fn( )} />,
+    );
+
+    expect( screen.getByTestId( "UniversalSearchResult.taxon.13" ) ).toBeTruthy( );
+    expect( screen.queryByTestId( "UniversalSearchResult.taxonImage" ) ).toBeNull( );
+    expect( screen.getByTestId( "IconicTaxonName.iconicTaxonIcon" ) ).toBeTruthy( );
+  } );
+
+  it( "renders a user result with its login and observation count", ( ) => {
+    renderComponent(
+      <UniversalSearchResult result={USER_RESULT} onPress={jest.fn( )} />,
+    );
+
+    expect( screen.getByTestId( "UniversalSearchResult.user.7" ) ).toBeTruthy( );
+    expect( screen.getByText( "seth_msp" ) ).toBeTruthy( );
+  } );
+
+  it( "renders a project result with its title", ( ) => {
+    renderComponent(
+      <UniversalSearchResult result={PROJECT_RESULT} onPress={jest.fn( )} />,
+    );
+
+    expect( screen.getByTestId( "UniversalSearchResult.project.9" ) ).toBeTruthy( );
+    expect( screen.getByText( "InverteFest" ) ).toBeTruthy( );
+  } );
+
+  it( "calls onPress when the row is tapped", ( ) => {
+    const onPress = jest.fn( );
+    renderComponent(
+      <UniversalSearchResult result={USER_RESULT} onPress={onPress} />,
+    );
+
+    fireEvent.press( screen.getByTestId( "UniversalSearchResult.user.7" ) );
+
+    expect( onPress ).toHaveBeenCalledTimes( 1 );
+  } );
+} );
diff --git a/tests/unit/components/Explore/ExploreV2/helpers/universalSearchSubject.test.js b/tests/unit/components/Explore/ExploreV2/helpers/universalSearchSubject.test.js
new file mode 100644
index 000000000..9c5b08aaf
--- /dev/null
+++ b/tests/unit/components/Explore/ExploreV2/helpers/universalSearchSubject.test.js
@@ -0,0 +1,113 @@
+import {
+  resultToSubject,
+  subjectToText,
+} from "components/Explore/ExploreV2/helpers/universalSearchSubject";
+
+describe( "resultToSubject", ( ) => {
+  it( "maps a user result to a user subject", ( ) => {
+    const result = {
+      type: "user",
+      user: {
+        id: 7,
+        login: "seth_msp",
+        icon_url: "https://example.com/u.jpg",
+        observations_count: 5,
+      },
+    };
+
+    expect( resultToSubject( result ) ).toEqual( {
+      type: "user",
+      user: {
+        id: 7,
+        login: "seth_msp",
+        icon_url: "https://example.com/u.jpg",
+      },
+    } );
+  } );
+
+  it( "maps a project result to a project subject", ( ) => {
+    const result = {
+      type: "project",
+      project: {
+        id: 9,
+        title: "InverteFest",
+        project_type: "collection",
+        icon: "https://example.com/p.jpg",
+      },
+    };
+
+    expect( resultToSubject( result ) ).toEqual( {
+      type: "project",
+      project: {
+        id: 9,
+        title: "InverteFest",
+        icon: "https://example.com/p.jpg",
+      },
+    } );
+  } );
+
+  it( "maps a taxon result to a taxon subject", ( ) => {
+    const result = {
+      type: "taxon",
+      taxon: {
+        id: 12,
+        name: "Eumyias thalassinus",
+        preferred_common_name: "Verditer Flycatcher",
+        iconic_taxon_name: "Aves",
+        default_photo: { url: "https://example.com/t.jpg" },
+      },
+    };
+
+    expect( resultToSubject( result ) ).toEqual( {
+      type: "taxon",
+      taxon: {
+        id: 12,
+        name: "Eumyias thalassinus",
+        preferred_common_name: "Verditer Flycatcher",
+        iconic_taxon_name: "Aves",
+        default_photo: { url: "https://example.com/t.jpg" },
+      },
+    } );
+  } );
+} );
+
+describe( "subjectToText", ( ) => {
+  it( "returns the login for a user subject", ( ) => {
+    const subject = { type: "user", user: { id: 7, login: "seth_msp" } };
+
+    expect( subjectToText( subject, true ) ).toEqual( "seth_msp" );
+  } );
+
+  it( "returns the title for a project subject", ( ) => {
+    const subject = { type: "project", project: { id: 9, title: "InverteFest" } };
+
+    expect( subjectToText( subject, true ) ).toEqual( "InverteFest" );
+  } );
+
+  it( "returns the common name for a taxon when the common name is primary", ( ) => {
+    const subject = {
+      type: "taxon",
+      taxon: { id: 2, name: "Aves", preferred_common_name: "Birds" },
+    };
+
+    expect( subjectToText( subject, true ) ).toEqual( "Birds" );
+  } );
+
+  it( "returns the scientific name for a taxon when the scientific name is primary", ( ) => {
+    const subject = {
+      type: "taxon",
+      taxon: { id: 2, name: "Aves", preferred_common_name: "Birds" },
+    };
+
+    expect( subjectToText( subject, false ) ).toEqual( "Aves" );
+  } );
+
+  it( "falls back to the scientific name when there is no common name", ( ) => {
+    const subject = {
+      type: "taxon",
+      taxon: { id: 2, name: "Aves" },
+    };
+
+    expect( subjectToText( subject, true ) ).toEqual( "Aves" );
+  } );
+} );
diff --git a/tests/unit/components/Explore/ExploreV2/screens/UniversalSearch.test.js b/tests/unit/components/Explore/ExploreV2/screens/UniversalSearch.test.js
index f157a9349..3c7edcae4 100644
--- a/tests/unit/components/Explore/ExploreV2/screens/UniversalSearch.test.js
+++ b/tests/unit/components/Explore/ExploreV2/screens/UniversalSearch.test.js
@@ -51,7 +51,7 @@ const MIXED_RESULTS = [
     type: "user",
     user: {
       id: 7,
-      login: "carrieseltzer",
+      login: "seth_msp",
       icon_url: "https://example.com/u.jpg",
       observations_count: 5,
     },
@@ -147,7 +147,7 @@ describe( "UniversalSearch screen", ( ) => {
 
     typeQuery( "ver" );
 
-    expect( screen.getByText( "carrieseltzer" ) ).toBeTruthy( );
+    expect( screen.getByText( "seth_msp" ) ).toBeTruthy( );
     expect( screen.getByText( "InverteFest" ) ).toBeTruthy( );
     expect( screen.getByTestId( "UniversalSearchResult.taxon.12" ) ).toBeTruthy( );
     // each row has a (no-op) info icon
@@ -171,12 +171,12 @@ describe( "UniversalSearch screen", ( ) => {
         type: "SET_SUBJECT",
         subject: expect.objectContaining( {
           type: "user",
-          user: expect.objectContaining( { id: 7, login: "carrieseltzer" } ),
+          user: expect.objectContaining( { id: 7, login: "seth_msp" } ),
         } ),
       } ),
     );
     // the search field is filled with the selected suggestion
-    expect( screen.getByDisplayValue( "carrieseltzer" ) ).toBeTruthy( );
+    expect( screen.getByDisplayValue( "seth_msp" ) ).toBeTruthy( );
   } );
 
   it( "clears the field but keeps the subject when tapping back in after a selection", ( ) => {
@@ -189,17 +189,55 @@ describe( "UniversalSearch screen", ( ) => {
 
     typeQuery( "ver" );
     fireEvent.press( screen.getByTestId( "UniversalSearchResult.user.7" ) );
-    expect( screen.getByDisplayValue( "carrieseltzer" ) ).toBeTruthy( );
+    expect( screen.getByDisplayValue( "seth_msp" ) ).toBeTruthy( );
 
     mockDispatch.mockClear( );
     fireEvent( screen.getByTestId( "UniversalSearch.subjectInput" ), "focus" );
 
     // the field is cleared for a fresh search...
-    expect( screen.queryByDisplayValue( "carrieseltzer" ) ).toBeNull( );
+    expect( screen.queryByDisplayValue( "seth_msp" ) ).toBeNull( );
     // ...but the committed subject persists (only Reset / a new selection clears it)
     expect( mockDispatch ).not.toHaveBeenCalledWith( { type: "CLEAR_SUBJECT" } );
   } );
 
+  it( "shows an empty-state message when a query returns no results", ( ) => {
+    useUniversalSearch.mockReturnValue( { results: [], isLoading: false, refetch: jest.fn( ) } );
+    renderComponent( <UniversalSearch /> );
+
+    typeQuery( "zzzzz" );
+
+    expect(
+      screen.getByText( i18next.t( "No-results-found-for-that-search" ) ),
+    ).toBeTruthy( );
+  } );
+
+  it( "does not show the empty-state message while results are loading", ( ) => {
+    useUniversalSearch.mockReturnValue( { results: [], isLoading: true, refetch: jest.fn( ) } );
+    renderComponent( <UniversalSearch /> );
+
+    typeQuery( "ver" );
+
+    expect(
+      screen.queryByText( i18next.t( "No-results-found-for-that-search" ) ),
+    ).toBeNull( );
+  } );
+
+  it( "does not show results until the user has typed a query", ( ) => {
+    useUniversalSearch.mockReturnValue( {
+      results: MIXED_RESULTS,
+      isLoading: false,
+      refetch: jest.fn( ),
+    } );
+    renderComponent( <UniversalSearch /> );
+
+    // No query typed yet, so the result list is not rendered even though the
+    // hook would return data.
+    expect( screen.queryByText( "seth_msp" ) ).toBeNull( );
+    expect(
+      screen.queryByText( i18next.t( "No-results-found-for-that-search" ) ),
+    ).toBeNull( );
+  } );
+
   it( "navigates to Advanced Search", ( ) => {
     renderComponent( <UniversalSearch /> );
 
diff --git a/tests/unit/sharedHooks/useDebouncedValue.test.js b/tests/unit/sharedHooks/useDebouncedValue.test.js
new file mode 100644
index 000000000..b93161707
--- /dev/null
+++ b/tests/unit/sharedHooks/useDebouncedValue.test.js
@@ -0,0 +1,90 @@
+import { act, renderHook } from "@testing-library/react-native";
+import useDebouncedValue from "sharedHooks/useDebouncedValue";
+
+const DELAY = 400;
+
+beforeEach( ( ) => {
+  jest.useFakeTimers( );
+} );
+
+afterEach( ( ) => {
+  jest.useRealTimers( );
+} );
+
+describe( "useDebouncedValue", ( ) => {
+  it( "returns the initial value immediately", ( ) => {
+    const { result } = renderHook( ( ) => useDebouncedValue( "start", DELAY ) );
+
+    expect( result.current.debouncedValue ).toEqual( "start" );
+  } );
+
+  it( "does not update the value until the delay elapses", ( ) => {
+    const { result } = renderHook( ( ) => useDebouncedValue( "", DELAY ) );
+
+    act( ( ) => {
+      result.current.debounce( "later" );
+      jest.advanceTimersByTime( DELAY - 1 );
+    } );
+
+    expect( result.current.debouncedValue ).toEqual( "" );
+
+    act( ( ) => {
+      jest.advanceTimersByTime( 1 );
+    } );
+
+    expect( result.current.debouncedValue ).toEqual( "later" );
+  } );
+
+  it( "coalesces rapid calls so only the last value lands", ( ) => {
+    const { result } = renderHook( ( ) => useDebouncedValue( "", DELAY ) );
+
+    act( ( ) => {
+      result.current.debounce( "a" );
+      jest.advanceTimersByTime( DELAY - 100 );
+      // A second call before the first fired resets the timer.
+      result.current.debounce( "b" );
+      jest.advanceTimersByTime( DELAY - 100 );
+    } );
+
+    // The pending "a" was cancelled, and "b" hasn't reached its full delay yet.
+    expect( result.current.debouncedValue ).toEqual( "" );
+
+    act( ( ) => {
+      jest.advanceTimersByTime( 100 );
+    } );
+
+    expect( result.current.debouncedValue ).toEqual( "b" );
+  } );
+
+  it( "setImmediately applies the value now and cancels a pending debounce", ( ) => {
+    const { result } = renderHook( ( ) => useDebouncedValue( "", DELAY ) );
+
+    act( ( ) => {
+      result.current.debounce( "pending" );
+      result.current.setImmediately( "now" );
+    } );
+
+    expect( result.current.debouncedValue ).toEqual( "now" );
+
+    // The pending debounce must not overwrite the immediate value later.
+    act( ( ) => {
+      jest.advanceTimersByTime( DELAY );
+    } );
+
+    expect( result.current.debouncedValue ).toEqual( "now" );
+  } );
+
+  it( "cancels a pending debounce on unmount", ( ) => {
+    const clearTimeoutSpy = jest.spyOn( global, "clearTimeout" );
+    const { result, unmount } = renderHook( ( ) => useDebouncedValue( "", DELAY ) );
+
+    act( ( ) => {
+      result.current.debounce( "never" );
+    } );
+
+    unmount( );
+
+    expect( clearTimeoutSpy ).toHaveBeenCalled( );
+    clearTimeoutSpy.mockRestore( );
+  } );
+} );
diff --git a/tests/unit/sharedHooks/useUniversalSearch.test.js b/tests/unit/sharedHooks/useUniversalSearch.test.js
new file mode 100644
index 000000000..0ed3f1d1e
--- /dev/null
+++ b/tests/unit/sharedHooks/useUniversalSearch.test.js
@@ -0,0 +1,73 @@
+import { waitFor } from "@testing-library/react-native";
+import useUniversalSearch from "sharedHooks/useUniversalSearch";
+import { renderHookInApp } from "tests/helpers/render";
+
+jest.mock( "api/search" );
+const { search } = require( "api/search" );
+
+const TAXON_RESULT = {
+  taxon: {
+    id: 12,
+    name: "Eumyias thalassinus",
+    preferred_common_name: "Verditer Flycatcher",
+  },
+};
+const USER_RESULT = {
+  user: { id: 7, login: "seth_msp" },
+};
+const PROJECT_RESULT = {
+  project: { id: 9, title: "InverteFest" },
+};
+
+beforeEach( ( ) => {
+  search.mockReset( );
+} );
+
+describe( "useUniversalSearch", ( ) => {
+  it( "does not query and returns no results for a blank query", async ( ) => {
+    const { result } = renderHookInApp( ( ) => useUniversalSearch( "   " ) );
+
+    // Give the (disabled) query a chance to fire if it were going to.
+    await waitFor( ( ) => expect( result.current.isLoading ).toBe( false ) );
+
+    expect( search ).not.toHaveBeenCalled( );
+    expect( result.current.results ).toEqual( [] );
+  } );
+
+  it( "trims the query before sending it to the API", async ( ) => {
+    search.mockResolvedValue( { results: [] } );
+
+    renderHookInApp( ( ) => useUniversalSearch( "  ver  " ) );
+
+    await waitFor( ( ) => expect( search ).toHaveBeenCalled( ) );
+    expect( search ).toHaveBeenCalledWith(
+      expect.objectContaining( { q: "ver", sources: ["taxa", "users", "projects"] } ),
+      expect.anything( ),
+    );
+  } );
+
+  it( "maps a mixed response to a tagged union, preserving order", async ( ) => {
+    search.mockResolvedValue( {
+      results: [USER_RESULT, TAXON_RESULT, PROJECT_RESULT],
+    } );
+
+    const { result } = renderHookInApp( ( ) => useUniversalSearch( "ver" ) );
+
+    await waitFor( ( ) => expect( result.current.results.length ).toEqual( 3 ) );
+
+    expect( result.current.results ).toEqual( [
+      { type: "user", user: USER_RESULT.user },
+      { type: "taxon", taxon: TAXON_RESULT.taxon },
+      { type: "project", project: PROJECT_RESULT.project },
+    ] );
+  } );
+
+  it( "returns an empty list when the API responds with null", async ( ) => {
+    search.mockResolvedValue( null );
+
+    const { result } = renderHookInApp( ( ) => useUniversalSearch( "ver" ) );
+
+    await waitFor( ( ) => expect( search ).toHaveBeenCalled( ) );
+    expect( result.current.results ).toEqual( [] );
+  } );
+} );