Add unit test run to the CI

.travis.yml

@@ -5,4 +5,6 @@ os:
 compiler:
   - gcc
   - clang
-script: make
+script:
+  - make
+  - test/unittest/run_all.sh

test/unittest/run_all.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+# This script is intended to be used either by the CI or by a developer that
+# wants to check that no unit tests have been broken to ensure there are no
+# regressions. At the end, it reports how many tests were successful. However,
+# using grep we can easily filter out everything except for those tests that
+# time out. e.g. ./run_all.sh | grep -i timeout -B1
+
+set -u -o pipefail
+
+readonly SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+readonly GRAVITY_BIN=$SCRIPT_DIR/../../gravity
+files=$(find $SCRIPT_DIR -iname "*.gravity" | grep -v disabled)
+tests_total=$(echo "$files" | wc -l)
+tests_success=0
+tests_fail=0
+tests_timeout=0
+i=1
+
+for test in $files; do
+    echo "Testing $i/$tests_total - $test..."
+    # Set 0.1s by default, but fallback to 10s in case of memory or recursion test
+    timeout=0.1
+    if [[ "$test" =~ "mem" || "$test" =~ "recursion" ]]; then
+        timeout=10
+    fi
+    timeout $timeout "$GRAVITY_BIN" "$test"
+    res=$?
+    if [[ $res -eq 0 ]]; then
+        tests_success=$(($tests_success+1))
+        echo "Success!"
+    elif [[ $res -eq 124 ]]; then
+        echo "Timeout!"
+        tests_timeout=$(($tests_timeout+1))
+    else
+        echo "Fail!"
+        tests_fail=$(($tests_fail+1))
+    fi
+    i=$(($i+1))
+done
+
+echo "Tests run successfully: $tests_success/$tests_total. $tests_fail failed and $tests_timeout timed out"
+
+if [[ $(($tests_fail+$tests_timeout)) -ne 0 ]]; then
+    exit 1
+fi