Add parallel tests (#192)

Uses pg_regress  to run tests in parallel against the database.
Allows custom DB initialization and finalization which can be used to load relevant data in the beginning
and check relevant invariants in the end

ci/scripts/run-tests-linux.sh

@@ -27,6 +27,7 @@ function run_db_tests(){
   then
     cd $WORKDIR/build && \
     make test && \
+    make test-parallel && \
     killall postgres && \
     gcovr -r $WORKDIR/src/ --object-directory $WORKDIR/build/ --xml /tmp/coverage.xml
   fi

test/test_runner.sh

@@ -27,6 +27,7 @@ function drop_db {
 EOF
 }
 
+<<<<<<< HEAD
 function run_regression_test {
      # Exclude debug/inconsistent output from psql
      # So tests will always have the same output
@@ -51,20 +52,36 @@ trap drop_db EXIT
 
 
 
-# Change directory to sql so sql imports will work correctly
+# If these aren't parallel tests always drop the db after the test
+# if they are though we only want to drop after end which is where we check invariants
+# this allows the parallel tests to be run against the same db 
+if [ "$PARALLEL" -eq 0 ]; then
+    trap drop_db EXIT
+elif [[ "$TESTFILE_NAME" =~ ^end ]]; then
+    trap drop_db EXIT
+fi
+
+
+# Change directory to sql directory so sql imports will work correctly
 cd sql/
 
 # install lantern extension
-psql "$@" -U ${DB_USER} -d postgres -v ECHO=none -q -c "DROP DATABASE IF EXISTS ${TEST_CASE_DB};" 2>/dev/null
-psql "$@" -U ${DB_USER} -d postgres -v ECHO=none -q -c "CREATE DATABASE ${TEST_CASE_DB};" 2>/dev/null
+# if tests are parallel we only do this for the begin tests as we won't be dropping the database until the end
+# begin will handle initialization specific to the tests but expects the database already exists
+if [ "$PARALLEL" -eq 0 ] || ( [[ "$TESTFILE_NAME" =~ ^begin ]] && [ "$PARALLEL" -eq 1 ] ); then
+    psql "$@" -U ${DB_USER} -d postgres -v ECHO=none -q -c "DROP DATABASE IF EXISTS ${TEST_CASE_DB};" 2>/dev/null
+    psql "$@" -U ${DB_USER} -d postgres -v ECHO=none -q -c "CREATE DATABASE ${TEST_CASE_DB};" 2>/dev/null
+    psql "$@" -U ${DB_USER} -d ${TEST_CASE_DB} -v ECHO=none -q -c "SET client_min_messages=error; CREATE EXTENSION lantern;" 2>/dev/null
+    psql "$@" -U ${DB_USER} -d ${TEST_CASE_DB} -v ECHO=none -q -f utils/common.sql 2>/dev/null
+fi
+
 if [ ! -z "$UPDATE_EXTENSION" ]
 then
      if [ -z "$UPDATE_FROM" ] || [ -z "$UPDATE_TO" ]
      then
           echo "ERROR: UPDATE_FROM and UPDATE_TO environment variables must be set before test_runner.sh whenever UPDATE_EXTENSION is set"
           exit 1
      fi
-
      # install the old version of the extension and sanity-check that all tests pass
      psql "$@" -U ${DB_USER} -d ${TEST_CASE_DB} -v ECHO=none -q -c "SET client_min_messages=error; CREATE EXTENSION lantern VERSION '$UPDATE_FROM';" 2>/dev/null
      psql "$@" -U ${DB_USER} -d ${TEST_CASE_DB} -v ECHO=none -q -f utils/common.sql 2>/dev/null