Do not consider PG array columns as number or text columns

The code uses these checks in several places to know what to do with a
particular column, for instance AR attribute query methods has a branch
like this:

    if column.number?
      !value.zero?
    end

This should never be true for array columns, since it would be the same
as running [].zero?, which results in a NoMethodError exception.

Fixing this by ensuring that array columns in PostgreSQL never return
true for number?/text? checks.

Since most of the array support was based on the postgres_ext lib, it's
worth noting it does the same thing for numeric array columns too:

https://github.com/dockyard/postgres_ext/blob/v1.0.0/lib/postgres_ext/active_record/connection_adapters/postgres_adapter.rb#L72

This extended the same logic for text columns to ensure consistency.

1 files changed, 6 insertions, 2 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/array_test.rb b/activerecord/test/cases/adapters/postgresql/array_test.rb
index 114d5b6cc6..b0870e2256 100644
--- a/activerecord/test/cases/adapters/postgresql/array_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/array_test.rb
@@ -26,6 +26,12 @@ class PostgresqlArrayTest < ActiveRecord::TestCase
   def test_column
     assert_equal :string, @column.type
     assert @column.array
+    assert_not @column.text?
+
+    ratings_column = PgArray.columns_hash['ratings']
+    assert_equal :integer, ratings_column.type
+    assert ratings_column.array
+    assert_not ratings_column.number?
   end
 
   def test_change_column_with_array
@@ -50,8 +56,6 @@ class PostgresqlArrayTest < ActiveRecord::TestCase
   end
 
   def test_type_cast_array
-    assert @column
-
     data = '{1,2,3}'
     oid_type  = @column.instance_variable_get('@oid_type').subtype
     # we are getting the instance variable in this test, but in the