dataconnect: emulator.sh: add fancy command-line argument parsing to improve devx

firebase-dataconnect/emulator/emulator.sh

@@ -16,18 +16,121 @@
 
 set -euo pipefail
 
-# Uncomment the line below to use a custom Data Connect Emulator binary
-#export DATACONNECT_EMULATOR_BINARY_PATH='...'
+readonly SCRIPT_DIR="$(dirname "$0")"
+readonly SELF_EXECUTABLE="$0"
+readonly LOG_PREFIX="[$0] "
+readonly DEFAULT_POSTGRESQL_STRING='postgresql://postgres:postgres@localhost:5432?sslmode=disable'
 
-export FIREBASE_DATACONNECT_POSTGRESQL_STRING='postgresql://postgres:postgres@localhost:5432?sslmode=disable'
-echo "[$0] export FIREBASE_DATACONNECT_POSTGRESQL_STRING='$FIREBASE_DATACONNECT_POSTGRESQL_STRING'"
+function main {
+  parse_args "$@"
 
-readonly FIREBASE_ARGS=(
-  firebase
-  --debug
-  emulators:start
-  --only auth,dataconnect
-)
+  log "FIREBASE_DATACONNECT_POSTGRESQL_STRING=${FIREBASE_DATACONNECT_POSTGRESQL_STRING:-<undefined>}"
+  log "DATACONNECT_EMULATOR_BINARY_PATH=${DATACONNECT_EMULATOR_BINARY_PATH:-<undefined>}"
 
-echo "[$0] Running command: ${FIREBASE_ARGS[*]}"
-exec "${FIREBASE_ARGS[@]}"
+  readonly FIREBASE_ARGS=(
+    firebase
+    --debug
+    emulators:start
+    --only auth,dataconnect
+  )
+
+  log "Running command: ${FIREBASE_ARGS[*]}"
+  exec "${FIREBASE_ARGS[@]}"
+}
+
+function parse_args {
+  local emulator_binary=''
+  local postgresql_string="${DEFAULT_POSTGRESQL_STRING}"
+  local wipe_and_restart_postgres_pod=0
+
+  local OPTIND=1
+  local OPTERR=0
+  while getopts ":c:p:hw" arg ; do
+    case "$arg" in
+      c) emulator_binary="${OPTARG}" ;;
+      p) postgresql_string="${OPTARG}" ;;
+      w) wipe_and_restart_postgres_pod=1 ;;
+      h)
+        print_help
+        exit 0
+        ;;
+      :)
+        echo "ERROR: missing value after option: -${OPTARG}" >&2
+        echo "Run with -h for help" >&2
+        exit 2
+        ;;
+      ?)
+        echo "ERROR: unrecognized option: -${OPTARG}" >&2
+        echo "Run with -h for help" >&2
+        exit 2
+        ;;
+      *)
+        echo "INTERNAL ERROR: unknown argument: $arg" >&2
+        exit 1
+        ;;
+    esac
+  done
+
+  if [[ ! -z $emulator_binary ]] ; then
+    export DATACONNECT_EMULATOR_BINARY_PATH="${emulator_binary}"
+  fi
+
+  if [[ ! -z $postgresql_string ]] ; then
+    export FIREBASE_DATACONNECT_POSTGRESQL_STRING="${postgresql_string}"
+  fi
+
+  if [[ $wipe_and_restart_postgres_pod == "1" ]] ; then
+    local wipe_args="${SCRIPT_DIR}/wipe_postgres_db.sh"
+    log "Running command: ${wipe_args[*]}"
+    "${wipe_args[@]}"
+
+    local start_args="${SCRIPT_DIR}/start_postgres_pod.sh"
+    log "Running command: ${start_args[*]}"
+    "${start_args[@]}"
+  fi
+}
+
+function print_help {
+  echo "Firebase Data Connect Emulator Launcher Helper"
+  echo
+  echo "This script provides a convenient way to launch the Firebase Data Connect"
+  echo "and Firebase Authentication emulators in a way that is amenable for running"
+  echo "the integration tests."
+  echo
+  echo "Syntax: ${SELF_EXECUTABLE} [options]"
+  echo
+  echo "Options:"
+  echo "  -c <data_connect_emulator_binary_path>"
+  echo "    Uses the Data Connect Emulator binary at the given path. If not specified, "
+  echo "    or if specified as the empty string, then the emulator binary is downloaded."
+  echo
+  echo "  -p <postgresql_connection_string>"
+  echo "    Uses the given string to connect to the PostgreSQL server. If not specified "
+  echo "    the the default value of \"${DEFAULT_POSTGRESQL_STRING}\" is used."
+  echo "    If specified as the empty string then an ephemeral PGLite server is used."
+  echo
+  echo "  -w"
+  echo "    If specified, then a local PostgreSQL container is wiped and restarted"
+  echo "    before launching the emulators. This is accomplished by running the scripts"
+  echo "    ./wipe_postgres_db.sh followed by ./start_postgres_pod.sh."
+  echo
+  echo "  -h"
+  echo "    Print this help screen and exit, as if successful."
+  echo
+  echo "Environment Variables:"
+  echo "  DATACONNECT_EMULATOR_BINARY_PATH"
+  echo "    This variable will be set to the value of the -c argument prior to launching"
+  echo "    the emulators. If the -c argument is not given then the value of this environment"
+  echo "    variable will be used as if it had been specified to the -c argument."
+  echo
+  echo "  FIREBASE_DATACONNECT_POSTGRESQL_STRING"
+  echo "    This variable will be set to the value of the -p argument prior to launching"
+  echo "    the emulators. If the -p argument is not given then the value of this environment"
+  echo "    variable will be set to \"${DEFAULT_POSTGRESQL_STRING}\"."
+}
+
+function log {
+  echo "${LOG_PREFIX}$*"
+}
+
+main "$@"