tests: Restore `runnerBackend.sh` (#4803)

* tests: Restore `runnerBackend.sh`

`runnerBackend.sh` was deleted in commit
7dae5e3db8 but plugins still need it
until their GitHub workflow definitions have been updated.

Co-authored-by: John McLear <john@mclear.co.uk>

src/bin/plugins/lib/backend-tests.yml

@@ -46,5 +46,5 @@ jobs:
     - name: Run the backend tests
       run: cd src && npm test
 
-##ETHERPAD_NPM_V=1
+##ETHERPAD_NPM_V=2
 ## NPM configuration automatically created using src/bin/plugins/updateAllPluginsScript.sh

src/tests/frontend/travis/runnerBackend.sh

@@ -0,0 +1,47 @@
+#!/bin/sh
+
+pecho() { printf %s\\n "$*"; }
+log() { pecho "$@"; }
+error() { log "ERROR: $@" >&2; }
+fatal() { error "$@"; exit 1; }
+try() { "$@" || fatal "'$@' failed"; }
+
+# Move to the Etherpad base directory.
+MY_DIR=$(try cd "${0%/*}" && try pwd -P) || exit 1
+try cd "${MY_DIR}/../../../.."
+
+try sed -e '
+s!"soffice":[^,]*!"soffice": "/usr/bin/soffice"!
+# Reduce rate limit aggressiveness
+s!"max":[^,]*!"max": 100!
+s!"points":[^,]*!"points": 1000!
+' settings.json.template >settings.json
+
+log "Deprecation notice: runnerBackend.sh - Please use: cd src && npm test"
+log "Assuming src/bin/installDeps.sh has already been run"
+node src/node/server.js "${@}" &
+ep_pid=$!
+
+log "Waiting for Etherpad to accept connections (http://localhost:9001)..."
+connected=false
+can_connect() {
+    curl -sSfo /dev/null http://localhost:9001/ || return 1
+    connected=true
+}
+now() { date +%s; }
+start=$(now)
+while [ $(($(now) - $start)) -le 15 ] && ! can_connect; do
+    sleep 1
+done
+[ "$connected" = true ] \
+    || fatal "Timed out waiting for Etherpad to accept connections"
+log "Successfully connected to Etherpad on http://localhost:9001"
+
+log "Running the backend tests..."
+try cd src
+npm test
+exit_code=$?
+
+kill "$ep_pid" && wait "$ep_pid"
+log "Done."
+exit "$exit_code"