Merge pull request #2788 from gnzlbg/test_check_fmt

test cargo fmt --all -- --check returns success after formatting

.travis.yml

@@ -31,19 +31,18 @@ matrix:
     - env: INTEGRATION=rand
     - env: INTEGRATION=rust-clippy
     - env: INTEGRATION=rust-semverver
-    - env: INTEGRATION=stdsimd
     - env: INTEGRATION=tempdir
   allow_failures:
-    # Need to run an lalrpop build step before testing?
+    # See: https://github.com/rust-lang-nursery/rustfmt/issues/2789
     - env: INTEGRATION=chalk
     # PR sent
     - env: INTEGRATION=crater
     # #2721
     - env: INTEGRATION=rand
     # Doesn't build
     - env: INTEGRATION=rust-clippy
-    # Doesn't build
-    - env: INTEGRATION=rust-semverver
+    # See: https://github.com/rust-lang-nursery/rustfmt/issues/2787
+    - env: INTEGRATION=stdsimd
 
 before_script:
 - |

ci/integration.sh

@@ -20,10 +20,15 @@ cargo install --force
 echo "Integration tests for: ${INTEGRATION}"
 cargo fmt -- --version
 
+# Checks that:
+#
+# * `cargo fmt --all` succeeds without any warnings or errors
+# * `cargo fmt --all -- --check` after formatting returns success
+# * `cargo test -all` still passes (formatting did not break the build)
 function check_fmt {
     touch rustfmt.toml
-    cargo fmt --all -v 2>&1 | tee rustfmt_output
-    if [[ $? != 0 ]]; then
+    cargo fmt --all -v |& tee rustfmt_output
+    if [[ ${PIPESTATUS[0]} != 0 ]]; then
         cat rustfmt_output
         return 1
     fi
@@ -40,6 +45,11 @@ function check_fmt {
     if [[ $? != 0 ]]; then
         return 1
     fi
+    cargo fmt --all -- --check |& tee rustfmt_check_output
+    if [[ ${PIPESTATUS[0]} != 0 ]]; then
+        cat rustfmt_check_output
+        return 1
+    fi
     cargo test --all
     if [[ $? != 0 ]]; then
         return $?