Merge branch 'hashtag-search' into 'develop'

Fix Hashtag search

See merge request pleroma/pleroma!4389

changelog.d/hashtag-search.change

@@ -0,0 +1 @@
+Hashtag searches return real results based on words in your query

lib/pleroma/hashtag.ex

@@ -130,4 +130,66 @@ defmodule Pleroma.Hashtag do
   end
 
   def get_recipients_for_activity(_activity), do: []
+
+  def search(query, options \\ []) do
+    limit = Keyword.get(options, :limit, 20)
+    offset = Keyword.get(options, :offset, 0)
+
+    search_terms =
+      query
+      |> String.downcase()
+      |> String.trim()
+      |> String.split(~r/\s+/)
+      |> Enum.filter(&(&1 != ""))
+      |> Enum.map(&String.trim_leading(&1, "#"))
+      |> Enum.filter(&(&1 != ""))
+
+    if Enum.empty?(search_terms) do
+      []
+    else
+      # Use PostgreSQL's ANY operator with array for efficient multi-term search
+      # This is much more efficient than multiple OR clauses
+      search_patterns = Enum.map(search_terms, &"%#{&1}%")
+
+      # Create ranking query that prioritizes exact matches and closer matches
+      # Use a subquery to properly handle computed columns in ORDER BY
+      base_query =
+        from(ht in Hashtag,
+          where: fragment("LOWER(?) LIKE ANY(?)", ht.name, ^search_patterns),
+          select: %{
+            name: ht.name,
+            # Ranking: exact matches get highest priority (0)
+            # then prefix matches (1), then contains (2)
+            match_rank:
+              fragment(
+                """
+                  CASE
+                    WHEN LOWER(?) = ANY(?) THEN 0
+                    WHEN LOWER(?) LIKE ANY(?) THEN 1
+                    ELSE 2
+                  END
+                """,
+                ht.name,
+                ^search_terms,
+                ht.name,
+                ^Enum.map(search_terms, &"#{&1}%")
+              ),
+            # Secondary sort by name length (shorter names first)
+            name_length: fragment("LENGTH(?)", ht.name)
+          }
+        )
+
+      from(result in subquery(base_query),
+        order_by: [
+          asc: result.match_rank,
+          asc: result.name_length,
+          asc: result.name
+        ],
+        limit: ^limit,
+        offset: ^offset
+      )
+      |> Repo.all()
+      |> Enum.map(& &1.name)
+    end
+  end
 end

lib/pleroma/web/mastodon_api/controllers/search_controller.ex

@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.MastodonAPI.SearchController do
   use Pleroma.Web, :controller
 
+  alias Pleroma.Hashtag
   alias Pleroma.Repo
   alias Pleroma.User
   alias Pleroma.Web.ControllerHelper
@@ -120,69 +121,14 @@ defmodule Pleroma.Web.MastodonAPI.SearchController do
   defp resource_search(:v2, "hashtags", query, options) do
     tags_path = Endpoint.url() <> "/tag/"
 
-    query
+    Hashtag.search(query, options)
-    |> prepare_tags(options)
     |> Enum.map(fn tag ->
       %{name: tag, url: tags_path <> tag}
     end)
   end
 
   defp resource_search(:v1, "hashtags", query, options) do
-    prepare_tags(query, options)
+    Hashtag.search(query, options)
-  end
-
-  defp prepare_tags(query, options) do
-    tags =
-      query
-      |> preprocess_uri_query()
-      |> String.split(~r/[^#\w]+/u, trim: true)
-      |> Enum.uniq_by(&String.downcase/1)
-
-    explicit_tags = Enum.filter(tags, fn tag -> String.starts_with?(tag, "#") end)
-
-    tags =
-      if Enum.any?(explicit_tags) do
-        explicit_tags
-      else
-        tags
-      end
-
-    tags = Enum.map(tags, fn tag -> String.trim_leading(tag, "#") end)
-
-    tags =
-      if Enum.empty?(explicit_tags) && !options[:skip_joined_tag] do
-        add_joined_tag(tags)
-      else
-        tags
-      end
-
-    Pleroma.Pagination.paginate_list(tags, options)
-  end
-
-  defp add_joined_tag(tags) do
-    tags
-    |> Kernel.++([joined_tag(tags)])
-    |> Enum.uniq_by(&String.downcase/1)
-  end
-
-  # If `query` is a URI, returns last component of its path, otherwise returns `query`
-  defp preprocess_uri_query(query) do
-    if query =~ ~r/https?:\/\// do
-      query
-      |> String.trim_trailing("/")
-      |> URI.parse()
-      |> Map.get(:path)
-      |> String.split("/")
-      |> Enum.at(-1)
-    else
-      query
-    end
-  end
-
-  defp joined_tag(tags) do
-    tags
-    |> Enum.map(fn tag -> String.capitalize(tag) end)
-    |> Enum.join()
   end
 
   defp with_fallback(f, fallback \\ []) do

test/pleroma/hashtag_test.exs

@@ -14,4 +14,133 @@ defmodule Pleroma.HashtagTest do
       assert {:name, {"can't be blank", [validation: :required]}} in changeset.errors
     end
   end
+
+  describe "search_hashtags" do
+    test "searches hashtags by partial match" do
+      {:ok, _} = Hashtag.get_or_create_by_name("car")
+      {:ok, _} = Hashtag.get_or_create_by_name("racecar")
+      {:ok, _} = Hashtag.get_or_create_by_name("nascar")
+      {:ok, _} = Hashtag.get_or_create_by_name("bicycle")
+
+      results = Hashtag.search("car")
+      assert "car" in results
+      assert "racecar" in results
+      assert "nascar" in results
+      refute "bicycle" in results
+
+      results = Hashtag.search("race")
+      assert "racecar" in results
+      refute "car" in results
+      refute "nascar" in results
+      refute "bicycle" in results
+
+      results = Hashtag.search("nonexistent")
+      assert results == []
+    end
+
+    test "searches hashtags by multiple words in query" do
+      {:ok, _} = Hashtag.get_or_create_by_name("computer")
+      {:ok, _} = Hashtag.get_or_create_by_name("laptop")
+      {:ok, _} = Hashtag.get_or_create_by_name("desktop")
+      {:ok, _} = Hashtag.get_or_create_by_name("phone")
+
+      # Search for "new computer" - should return "computer"
+      results = Hashtag.search("new computer")
+      assert "computer" in results
+      refute "laptop" in results
+      refute "desktop" in results
+      refute "phone" in results
+
+      # Search for "computer laptop" - should return both
+      results = Hashtag.search("computer laptop")
+      assert "computer" in results
+      assert "laptop" in results
+      refute "desktop" in results
+      refute "phone" in results
+
+      # Search for "new phone" - should return "phone"
+      results = Hashtag.search("new phone")
+      assert "phone" in results
+      refute "computer" in results
+      refute "laptop" in results
+      refute "desktop" in results
+    end
+
+    test "supports pagination" do
+      {:ok, _} = Hashtag.get_or_create_by_name("alpha")
+      {:ok, _} = Hashtag.get_or_create_by_name("beta")
+      {:ok, _} = Hashtag.get_or_create_by_name("gamma")
+      {:ok, _} = Hashtag.get_or_create_by_name("delta")
+
+      results = Hashtag.search("a", limit: 2)
+      assert length(results) == 2
+
+      results = Hashtag.search("a", limit: 2, offset: 1)
+      assert length(results) == 2
+    end
+
+    test "handles matching many search terms" do
+      {:ok, _} = Hashtag.get_or_create_by_name("computer")
+      {:ok, _} = Hashtag.get_or_create_by_name("laptop")
+      {:ok, _} = Hashtag.get_or_create_by_name("phone")
+      {:ok, _} = Hashtag.get_or_create_by_name("tablet")
+
+      results = Hashtag.search("new fast computer laptop phone tablet device")
+      assert "computer" in results
+      assert "laptop" in results
+      assert "phone" in results
+      assert "tablet" in results
+    end
+
+    test "ranks results by match quality" do
+      {:ok, _} = Hashtag.get_or_create_by_name("my_computer")
+      {:ok, _} = Hashtag.get_or_create_by_name("computer_science")
+      {:ok, _} = Hashtag.get_or_create_by_name("computer")
+
+      results = Hashtag.search("computer")
+
+      # Exact match first
+      assert Enum.at(results, 0) == "computer"
+
+      # Prefix match would be next
+      assert Enum.at(results, 1) == "computer_science"
+
+      # worst match is last
+      assert Enum.at(results, 2) == "my_computer"
+    end
+
+    test "prioritizes shorter names when ranking is equal" do
+      # Create hashtags with same ranking but different lengths
+      {:ok, _} = Hashtag.get_or_create_by_name("car")
+      {:ok, _} = Hashtag.get_or_create_by_name("racecar")
+      {:ok, _} = Hashtag.get_or_create_by_name("nascar")
+
+      # Search for "car" - shorter names should come first
+      results = Hashtag.search("car")
+      # Shortest exact match first
+      assert Enum.at(results, 0) == "car"
+      assert "racecar" in results
+      assert "nascar" in results
+    end
+
+    test "handles hashtag symbols in search query" do
+      {:ok, _} = Hashtag.get_or_create_by_name("computer")
+      {:ok, _} = Hashtag.get_or_create_by_name("laptop")
+      {:ok, _} = Hashtag.get_or_create_by_name("phone")
+
+      results_with_hash = Hashtag.search("#computer #laptop")
+      results_without_hash = Hashtag.search("computer laptop")
+
+      assert results_with_hash == results_without_hash
+
+      results_mixed = Hashtag.search("#computer laptop #phone")
+      assert "computer" in results_mixed
+      assert "laptop" in results_mixed
+      assert "phone" in results_mixed
+
+      results_only_hash = Hashtag.search("#computer")
+      results_no_hash = Hashtag.search("computer")
+      assert results_only_hash == results_no_hash
+    end
+  end
 end

test/pleroma/web/mastodon_api/controllers/search_controller_test.exs

@@ -7,7 +7,6 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
 
   alias Pleroma.Object
   alias Pleroma.Web.CommonAPI
-  alias Pleroma.Web.Endpoint
   import Pleroma.Factory
   import ExUnit.CaptureLog
   import Tesla.Mock
@@ -66,9 +65,7 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
       [account | _] = results["accounts"]
       assert account["id"] == to_string(user_three.id)
 
-      assert results["hashtags"] == [
+      assert results["hashtags"] == []
-               %{"name" => "private", "url" => "#{Endpoint.url()}/tag/private"}
-             ]
 
       [status] = results["statuses"]
       assert status["id"] == to_string(activity.id)
@@ -77,9 +74,7 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
         get(conn, "/api/v2/search?q=天子")
         |> json_response_and_validate_schema(200)
 
-      assert results["hashtags"] == [
+      assert results["hashtags"] == []
-               %{"name" => "天子", "url" => "#{Endpoint.url()}/tag/天子"}
-             ]
 
       [status] = results["statuses"]
       assert status["id"] == to_string(activity.id)
@@ -130,84 +125,97 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
       assert [] = results["statuses"]
     end
 
-    test "constructs hashtags from search query", %{conn: conn} do
+    test "returns empty results when no hashtags match", %{conn: conn} do
       results =
         conn
-        |> get("/api/v2/search?#{URI.encode_query(%{q: "some text with #explicit #hashtags"})}")
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "nonexistent"})}")
         |> json_response_and_validate_schema(200)
 
-      assert results["hashtags"] == [
+      assert results["hashtags"] == []
-               %{"name" => "explicit", "url" => "#{Endpoint.url()}/tag/explicit"},
+    end
-               %{"name" => "hashtags", "url" => "#{Endpoint.url()}/tag/hashtags"}
+
-             ]
+    test "searches hashtags by multiple words in query", %{conn: conn} do
+      user = insert(:user)
+
+      {:ok, _activity1} = CommonAPI.post(user, %{status: "This is my new #computer"})
+      {:ok, _activity2} = CommonAPI.post(user, %{status: "Check out this #laptop"})
+      {:ok, _activity3} = CommonAPI.post(user, %{status: "My #desktop setup"})
+      {:ok, _activity4} = CommonAPI.post(user, %{status: "New #phone arrived"})
 
       results =
         conn
-        |> get("/api/v2/search?#{URI.encode_query(%{q: "john doe JOHN DOE"})}")
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "new computer"})}")
         |> json_response_and_validate_schema(200)
 
-      assert results["hashtags"] == [
+      hashtag_names = Enum.map(results["hashtags"], & &1["name"])
-               %{"name" => "john", "url" => "#{Endpoint.url()}/tag/john"},
+      assert "computer" in hashtag_names
-               %{"name" => "doe", "url" => "#{Endpoint.url()}/tag/doe"},
+      refute "laptop" in hashtag_names
-               %{"name" => "JohnDoe", "url" => "#{Endpoint.url()}/tag/JohnDoe"}
+      refute "desktop" in hashtag_names
-             ]
+      refute "phone" in hashtag_names
 
       results =
         conn
-        |> get("/api/v2/search?#{URI.encode_query(%{q: "accident-prone"})}")
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "computer laptop"})}")
         |> json_response_and_validate_schema(200)
 
-      assert results["hashtags"] == [
+      hashtag_names = Enum.map(results["hashtags"], & &1["name"])
-               %{"name" => "accident", "url" => "#{Endpoint.url()}/tag/accident"},
+      assert "computer" in hashtag_names
-               %{"name" => "prone", "url" => "#{Endpoint.url()}/tag/prone"},
+      assert "laptop" in hashtag_names
-               %{"name" => "AccidentProne", "url" => "#{Endpoint.url()}/tag/AccidentProne"}
+      refute "desktop" in hashtag_names
-             ]
+      refute "phone" in hashtag_names
-
-      results =
-        conn
-        |> get("/api/v2/search?#{URI.encode_query(%{q: "https://shpposter.club/users/shpuld"})}")
-        |> json_response_and_validate_schema(200)
-
-      assert results["hashtags"] == [
-               %{"name" => "shpuld", "url" => "#{Endpoint.url()}/tag/shpuld"}
-             ]
-
-      results =
-        conn
-        |> get(
-          "/api/v2/search?#{URI.encode_query(%{q: "https://www.washingtonpost.com/sports/2020/06/10/" <> "nascar-ban-display-confederate-flag-all-events-properties/"})}"
-        )
-        |> json_response_and_validate_schema(200)
-
-      assert results["hashtags"] == [
-               %{"name" => "nascar", "url" => "#{Endpoint.url()}/tag/nascar"},
-               %{"name" => "ban", "url" => "#{Endpoint.url()}/tag/ban"},
-               %{"name" => "display", "url" => "#{Endpoint.url()}/tag/display"},
-               %{"name" => "confederate", "url" => "#{Endpoint.url()}/tag/confederate"},
-               %{"name" => "flag", "url" => "#{Endpoint.url()}/tag/flag"},
-               %{"name" => "all", "url" => "#{Endpoint.url()}/tag/all"},
-               %{"name" => "events", "url" => "#{Endpoint.url()}/tag/events"},
-               %{"name" => "properties", "url" => "#{Endpoint.url()}/tag/properties"},
-               %{
-                 "name" => "NascarBanDisplayConfederateFlagAllEventsProperties",
-                 "url" =>
-                   "#{Endpoint.url()}/tag/NascarBanDisplayConfederateFlagAllEventsProperties"
-               }
-             ]
     end
 
     test "supports pagination of hashtags search results", %{conn: conn} do
+      user = insert(:user)
+
+      {:ok, _activity1} = CommonAPI.post(user, %{status: "First #alpha hashtag"})
+      {:ok, _activity2} = CommonAPI.post(user, %{status: "Second #beta hashtag"})
+      {:ok, _activity3} = CommonAPI.post(user, %{status: "Third #gamma hashtag"})
+      {:ok, _activity4} = CommonAPI.post(user, %{status: "Fourth #delta hashtag"})
+
       results =
         conn
-        |> get(
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "a", limit: 2, offset: 1})}")
-          "/api/v2/search?#{URI.encode_query(%{q: "#some #text #with #hashtags", limit: 2, offset: 1})}"
-        )
         |> json_response_and_validate_schema(200)
 
-      assert results["hashtags"] == [
+      hashtag_names = Enum.map(results["hashtags"], & &1["name"])
-               %{"name" => "text", "url" => "#{Endpoint.url()}/tag/text"},
+
-               %{"name" => "with", "url" => "#{Endpoint.url()}/tag/with"}
+      # Should return 2 hashtags (alpha, beta, gamma, delta all contain 'a')
-             ]
+      # With offset 1, we skip the first one, so we get 2 of the remaining 3
+      assert length(hashtag_names) == 2
+      assert Enum.all?(hashtag_names, &String.contains?(&1, "a"))
+    end
+
+    test "searches real hashtags from database", %{conn: conn} do
+      user = insert(:user)
+
+      {:ok, _activity1} = CommonAPI.post(user, %{status: "Check out this #car"})
+      {:ok, _activity2} = CommonAPI.post(user, %{status: "Fast #racecar on the track"})
+      {:ok, _activity3} = CommonAPI.post(user, %{status: "NASCAR #nascar racing"})
+
+      results =
+        conn
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "car"})}")
+        |> json_response_and_validate_schema(200)
+
+      hashtag_names = Enum.map(results["hashtags"], & &1["name"])
+
+      # Should return car, racecar, and nascar since they all contain "car"
+      assert "car" in hashtag_names
+      assert "racecar" in hashtag_names
+      assert "nascar" in hashtag_names
+
+      # Search for "race" - should return racecar
+      results =
+        conn
+        |> get("/api/v2/search?#{URI.encode_query(%{q: "race"})}")
+        |> json_response_and_validate_schema(200)
+
+      hashtag_names = Enum.map(results["hashtags"], & &1["name"])
+
+      assert "racecar" in hashtag_names
+      refute "car" in hashtag_names
+      refute "nascar" in hashtag_names
     end
 
     test "excludes a blocked users from search results", %{conn: conn} do
@@ -314,7 +322,7 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
       [account | _] = results["accounts"]
       assert account["id"] == to_string(user_three.id)
 
-      assert results["hashtags"] == ["2hu"]
+      assert results["hashtags"] == []
 
       [status] = results["statuses"]
       assert status["id"] == to_string(activity.id)