build: update Travis CI to run a presubmit script

.travis.yml

@@ -21,21 +21,7 @@ before_install:
     rm -f install.sh
 
 script:
- - |
-    bazel \
-      --output_base=$HOME/.cache/bazel \
-      --batch \
-      --host_jvm_args=-Xmx500m \
-      --host_jvm_args=-Xms500m \
-      test \
-      --verbose_failures \
-      --sandbox_debug \
-      --test_output=errors \
-      --test_strategy=standalone \
-      --spawn_strategy=standalone \
-      --genrule_strategy=standalone \
-      --local_resources=400,1,1.0 \
-      //...
+ - ./presubmit.sh
 
 notifications:
   email: false

presubmit.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+echo ">>> Running all Bazel tests"
+bazel \
+    --output_base=$HOME/.cache/bazel \
+    --batch \
+    --host_jvm_args=-Xmx500m \
+    --host_jvm_args=-Xms500m \
+    test \
+    --verbose_failures \
+    --sandbox_debug \
+    --test_output=errors \
+    --test_strategy=standalone \
+    --spawn_strategy=standalone \
+    --genrule_strategy=standalone \
+    --local_resources=400,1,1.0 \
+    //...
+
+
+echo ">>> Running all examples"
+for label in $(bazel query //examples:all); do
+    bazel \
+        --output_base=$HOME/.cache/bazel \
+        --batch \
+        --host_jvm_args=-Xmx500m \
+        --host_jvm_args=-Xms500m \
+        run \
+        --verbose_failures \
+        --sandbox_debug \
+        --test_output=errors \
+        --test_strategy=standalone \
+        --spawn_strategy=standalone \
+        --genrule_strategy=standalone \
+        --local_resources=400,1,1.0 \
+        "$label"
+done
+
+
+echo ">>> All presubmit tests passed."