Statement#exec and #query require named argument for array values

This change allows to use an array as single argument for #exec and
 #query methods. Before it was shadowed by the *args splat overload.

spec/dummy_driver.cr

@@ -97,7 +97,7 @@ class DummyDriver < DB::Driver
     property params
 
     def initialize(connection, @query : String, @prepared : Bool)
-      @params = Hash(Int32 | String, DB::Any).new
+      @params = Hash(Int32 | String, DB::Any | Array(DB::Any)).new
       super(connection)
       raise DB::Error.new(query) if query == "syntax error"
     end
@@ -126,6 +126,10 @@ class DummyDriver < DB::Driver
       @params[index] = value
     end
 
+    private def set_param(index, value : Array)
+      @params[index] = value.map(&.as(DB::Any))
+    end
+
     private def set_param(index, value)
       raise "not implemented for #{value.class}"
     end

spec/statement_spec.cr

@@ -43,10 +43,18 @@ describe DB::Statement do
     end
   end
 
-  it "should initialize positional params in query with array" do
+  it "accepts array as single argument" do
     with_dummy_connection do |cnn|
       stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.query ["a", 1, nil]
+      stmt.params[0].should eq(["a", 1, nil])
+    end
+  end
+
+  it "should initialize positional params in query with array" do
+    with_dummy_connection do |cnn|
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
+      stmt.query args: ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
       stmt.params[2].should eq(nil)
@@ -63,10 +71,18 @@ describe DB::Statement do
     end
   end
 
-  it "should initialize positional params in exec with array" do
+  it "accepts array as single argument" do
     with_dummy_connection do |cnn|
       stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.exec ["a", 1, nil]
+      stmt.params[0].should eq(["a", 1, nil])
+    end
+  end
+
+  it "should initialize positional params in exec with array" do
+    with_dummy_connection do |cnn|
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
+      stmt.exec args: ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
       stmt.params[2].should eq(nil)

src/db/statement.cr

@@ -29,14 +29,14 @@ module DB
     # See `QueryMethods#exec`
     abstract def exec(*args) : ExecResult
     # See `QueryMethods#exec`
-    abstract def exec(args : Array) : ExecResult
+    abstract def exec(*, args : Array) : ExecResult
 
     # See `QueryMethods#query`
     abstract def query : ResultSet
     # See `QueryMethods#query`
     abstract def query(*args) : ResultSet
     # See `QueryMethods#query`
-    abstract def query(args : Array) : ResultSet
+    abstract def query(*, args : Array) : ResultSet
   end
 
   # Represents a query in a `Connection`.
@@ -68,7 +68,7 @@ module DB
     end
 
     # See `QueryMethods#exec`
-    def exec(args : Array) : DB::ExecResult
+    def exec(*, args : Array) : DB::ExecResult
       perform_exec_and_release(args)
     end
 
@@ -84,7 +84,7 @@ module DB
     end
 
     # See `QueryMethods#query`
-    def query(args : Array) : DB::ResultSet
+    def query(*, args : Array) : DB::ResultSet
       perform_query_with_rescue args
     end