do preRun and postRun only if we actually run

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/runner.py b/tests/runner.py
index fddcf1df..00c78a35 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -6539,6 +6539,29 @@ f.close()
       Popen(['python', EMCC, os.path.join(self.get_dir(), 'main.cpp'), '--pre-js', 'before.js', '--post-js', 'after.js']).communicate()
       self.assertContained('hello from main\nhello from js\n', run_js(os.path.join(self.get_dir(), 'a.out.js')))
 
+    def test_prepost(self):
+      open(os.path.join(self.get_dir(), 'main.cpp'), 'w').write('''
+        #include <stdio.h>
+        int main() {
+          printf("hello from main\\n");
+          return 0;
+        }
+      ''')
+      open(os.path.join(self.get_dir(), 'pre.js'), 'w').write('''
+        var Module = {
+          preRun: function() { Module.print('pre-run') },
+          postRun: function() { Module.print('post-run') }
+        };
+      ''')
+
+      Popen(['python', EMCC, os.path.join(self.get_dir(), 'main.cpp'), '--pre-js', 'pre.js']).communicate()
+      self.assertContained('pre-run\nhello from main\npost-run\n', run_js(os.path.join(self.get_dir(), 'a.out.js')))
+
+      # never run, so no preRun or postRun
+      src = open(os.path.join(self.get_dir(), 'a.out.js')).read().replace('// {{PRE_RUN_ADDITIONS}}', 'addRunDependency()')
+      open(os.path.join(self.get_dir(), 'a.out.js'), 'w').write(src)
+      self.assertNotContained('pre-run\nhello from main\npost-run\n', run_js(os.path.join(self.get_dir(), 'a.out.js')))
+
     def test_eliminator(self):
       input = open(path_from_root('tools', 'eliminator', 'eliminator-test.js')).read()
       expected = open(path_from_root('tools', 'eliminator', 'eliminator-test-output.js')).read()