unikernel/duniverse/dune_/test/blackbox-tests/test-cases/watching/retriggering.t

@@ -0,0 +1,36 @@
+Modify an input file during the build so that Dune interrupts the build once.
+
+  $ . ./helpers.sh
+
+Bad rule! You are not supposed to modify the source tree. No ice-cream for you!
+
+  $ mkdir test
+  $ cd test
+
+  $ echo '(lang dune 3.0)' > dune-project
+  $ cat > dune <<EOF
+  > (rule
+  >  (deps (glob_files *.txt) (sandbox none))
+  >  (alias default)
+  >  (action (system "\| echo "I'm seeing: %{deps}" >> ../../../output
+  >                  "\| touch ../../new-source.txt
+  > )))
+  > EOF
+
+  $ touch old-source.txt
+  $ start_dune
+
+  $ build .
+  Success
+
+We can see in the output below that the rule ran exactly twice. Note that the
+file watcher generates the next touch event for new-source.txt but it
+is ignored because the contents of new-source.txt is the same,
+i.e. the empty file.
+
+  $ cat ../output
+  I'm seeing: old-source.txt
+  I'm seeing: new-source.txt old-source.txt
+
+  $ stop_dune
+  Success, waiting for filesystem changes...