Allow numbers in literal/1 (#4562)

Author: greg-rychlewski

lib/ecto/query/api.ex

@@ -480,17 +480,20 @@ defmodule Ecto.Query.API do
   def fragment(fragments), do: doc!([fragments])
 
   @doc """
-  Allows a literal identifier to be injected into a fragment:
+  Allows a literal identifier or number to be injected into a fragment:
 
       collation = "es_ES"
       fragment("? COLLATE ?", ^name, literal(^collation))
 
-  The example above will inject `collation` into the query as
-  a literal identifier instead of a query parameter. Note that
-  each different value of `collation` will emit a different query,
-  which will be independently prepared and cached.
+      limit = 10
+      limit(query, fragment("?", literal(^limit)))
+
+  The example above will inject `collation` and `limit` into the queries as
+  literals instead of query parameters. Note that each different value passed
+  to `literal/1` will emit a different query, which will be independently prepared
+  and cached.
   """
-  def literal(binary), do: doc!([binary])
+  def literal(literal), do: doc!([literal])
 
   @doc """
   Allows a list argument to be spliced into a fragment.

lib/ecto/query/builder.ex

@@ -1256,13 +1256,12 @@ defmodule Ecto.Query.Builder do
   @doc """
   Called by escaper at runtime to verify literal in fragments.
   """
+  def literal!(literal) when is_binary(literal), do: literal
+  def literal!(literal) when is_number(literal), do: literal
+
   def literal!(literal) do
-    if is_binary(literal) do
-      literal
-    else
-      raise ArgumentError,
-            "literal(^value) expects `value` to be a string, got `#{inspect(literal)}`"
-    end
+    raise ArgumentError,
+          "literal(^value) expects `value` to be a string or a number, got `#{inspect(literal)}`"
   end
 
   @doc """

test/ecto/query_test.exs

@@ -988,9 +988,20 @@ defmodule Ecto.QueryTest do
                raw: ""
              ] = parts
 
-      assert_raise ArgumentError, "literal(^value) expects `value` to be a string, got `123`", fn ->
-        from p in "posts", select: fragment("? COLLATE ?", p.name, literal(^123))
-      end
+      query = from p in "posts", limit: fragment("?", literal(^1))
+      assert {:fragment, _, parts} = query.limit.expr
+
+      assert [
+               raw: "",
+               expr: {:literal, _, [1]},
+               raw: ""
+             ] = parts
+
+      assert_raise ArgumentError,
+                   "literal(^value) expects `value` to be a string or a number, got `%{}`",
+                   fn ->
+                     from p in "posts", select: fragment("? COLLATE ?", p.name, literal(^%{}))
+                   end
     end
 
     test "supports list splicing" do