testsuite: add t2620-job-shell-mustache.t

Problem: There are no specific tests for testing shell mustache
template expansion.

Add t2620-job-shell-mustache.t for this purpose.

t/Makefile.am

@@ -216,6 +216,7 @@ TESTSCRIPTS = \
 	t2617-job-shell-stage-in.t \
 	t2618-job-shell-signal.t \
 	t2619-job-shell-hwloc.t \
+	t2620-job-shell-mustache.t \
 	t2710-python-cli-submit.t \
 	t2711-python-cli-run.t \
 	t2713-python-cli-bulksubmit.t \

t/t2620-job-shell-mustache.t

@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+test_description='Test flux-shell mustache template rendering'
+
+. `dirname $0`/sharness.sh
+
+test_under_flux 2 job
+
+test_expect_success 'mustache: templates are rendered in job arguments' '
+	flux run -N2 -n4 \
+	  echo {{id.words}}: size={{size}} nnodes={{nnodes}} name={{name}} \
+	  >output.1 &&
+	test_debug "cat output.1" &&
+	grep "size=4 nnodes=2 name=echo" output.1
+'
+test_expect_success 'mustache: per-task tags work' '
+	flux run -N2 -n4 --label-io \
+	  echo rank={{task.rank}} index={{task.index}} \
+	  | sort >output.2 &&
+	test_debug "cat output.2" &&
+	cat <<-EOF >expected.2 &&
+	0: rank=0 index=0
+	1: rank=1 index=1
+	2: rank=2 index=0
+	3: rank=3 index=1
+	EOF
+	test_cmp expected.2 output.2
+'
+test_expect_success 'mustache: per-node tags work' '
+	flux run -N2 -n2 --label-io \
+	  echo id={{node.id}} name={{node.name}} cores={{node.cores}}[{{node.ncores}}] \
+	  | sort >output.3 &&
+	test_debug "cat output.3" &&
+	cat <<-EOF >expected.3 &&
+	0: id=0 name=$(hostname) cores=0[1]
+	1: id=1 name=$(hostname) cores=0[1]
+	EOF
+	test_cmp expected.3 output.3
+'
+test_expect_success 'mustache: unsupported tag is left alone' '
+	flux run echo {{foo}} {{node.foo}} {{task.foo}} >output.4 &&
+	test_debug "cat output.4" &&
+	test "$(cat output.4)" = "{{foo}} {{node.foo}} {{task.foo}}"
+'
+
+test_done