Add spec to ensure `schema.rb` keys are `bigint`s

We use `bigint`s by default for all primary and foreign keys in the
application.

Using `bigint`s provides two advantages:

* Matching the Java application, which expects `bigint`s
* Providing support for large integer identifiers

Here, we add a spec that checks the `schema.rb` file with line-by-line
string matching to validate that no primary or foreign keys use
non-`bigint` types.

The test is a bit rough at the moment, but it works against the
temporary migration included in this commit. It should be reworked,
though, to include line numbers of the problem fields.

Refs #4951

2 files changed, 38 insertions, 0 deletions

diff --git a/db/migrate/20171114110225_test_bad_foreign_keys.rb b/db/migrate/20171114110225_test_bad_foreign_keys.rb
new file mode 100644
index 000000000..0f2f5311b
--- /dev/null
+++ b/db/migrate/20171114110225_test_bad_foreign_keys.rb
@@ -0,0 +1,12 @@
+class TestBadForeignKeys < ActiveRecord::Migration
+  def change
+    create_table :bad_foreign_keys do |t|
+      t.string :thing
+      t.references :forei
+      t.integer :quant
+      t.references :anoth_for
+
+      t.timestamps null: false
+    end
+  end
+end
diff --git a/spec/db/schema_spec.rb b/spec/db/schema_spec.rb
new file mode 100644
index 000000000..8c5492cd7
--- /dev/null
+++ b/spec/db/schema_spec.rb
@@ -0,0 +1,26 @@
+RSpec.describe ActiveRecord::Schema do
+  it "uses type `bigint` for primary and foreign keys" do
+# grep -e 'create_table.*id: :bigserial' db/schema.rb | grep -v 'id: :bigserial'
+# grep -e 'create_table.+id: :bigserial' db/schema.rb | grep -v 'id: :bigserial'
+# grep -e  't\.integer *"\w*_id"' db/schema.rb | grep -v -e 'limit: 8'
+# grep -e  't\.integer +"\w+_id"' db/schema.rb | grep -v -e 'limit: 8'
+
+    non_bigint_primary_keys = []
+    non_bigint_foreign_keys = []
+
+    File.open('db/schema.rb', 'r') do |f|
+      non_bigint_primary_keys = f
+        .grep(/create_table /)
+        .grep_v(/id: :bigserial/)
+
+      f.rewind
+
+      non_bigint_foreign_keys = f
+        .grep(/t\.integer +"\w+_id"/)
+        .grep_v(/limit: 8/)
+    end
+
+    expect(non_bigint_primary_keys).to be_empty
+    expect(non_bigint_foreign_keys).to be_empty
+  end
+end