Allow SAFE_RUN to correctly run and check results

This shell function had several issues that prevented it from living up
to its name:

  1. It used `$1` to run commands, which fails to handle e.g. `;`
  1. It assigned using `local`, which would mask any errors
  3. It was invoked with command expansions, so anything it was supposed
     to run was already finished *before* it ran.

Author: koalaman

test/native-tests/test_native.sh

@@ -28,10 +28,11 @@ FIND_CLANG() {
 }
 
 SAFE_RUN() {
-    local SF_RETURN_VALUE=$($1 2>&1)
+    local SF_OUTPUT
+    SF_OUTPUT=$(eval "( $1 )" 2>&1)
 
     if [[ $? != 0 ]]; then
-        >&2 echo $SF_RETURN_VALUE
+        >&2 echo "$SF_OUTPUT"
         exit 1
     fi
 }
@@ -57,24 +58,24 @@ fi
 RUN () {
     TEST_PATH=$1
     echo "Testing $TEST_PATH"
-    SAFE_RUN `cd $TEST_PATH; ${CH_DIR} Platform.js > Makefile`
+    SAFE_RUN "cd $TEST_PATH && ${CH_DIR} Platform.js > Makefile"
     RES=$(cd $TEST_PATH; cat Makefile)
 
     if [[ $RES =~ "# IGNORE_THIS_TEST" ]]; then
         echo "Ignoring $TEST_PATH"
     else
-        SAFE_RUN `cd $TEST_PATH; make CC=${CC} CXX=${CXX}`
+        SAFE_RUN "cd $TEST_PATH && make CC=${CC} CXX=${CXX}"
         RES=$(cd $TEST_PATH; ./sample.o)
         TEST "SUCCESS"
-        SAFE_RUN `cd $TEST_PATH; rm -rf ./sample.o`
+        SAFE_RUN "cd $TEST_PATH && rm -rf ./sample.o"
     fi
 }
 
 RUN_CMD () {
     TEST_PATH=$1
     CMD=$2
     echo "Testing $TEST_PATH"
-    SAFE_RUN `cd $TEST_PATH; $CMD`
+    SAFE_RUN "cd $TEST_PATH && $CMD"
 }
 
 # static lib tests
@@ -100,4 +101,4 @@ RUN "test-shared-basic"
 # test python
 RUN_CMD "test-python" "python helloWorld.py ${BUILD_TYPE}"
 
-SAFE_RUN `rm -rf Makefile`
+SAFE_RUN "rm -rf Makefile"