Use esm for bench and test.

Author: jgm

Makefile

@@ -27,11 +27,11 @@ test: $(SPEC)
 	npm test
 
 bench:
-	node bench/bench.js ${BENCHINP}
+	node -r esm bench/bench.js ${BENCHINP}
 
 bench-detailed:
 	sudo renice -10 $$$$; \
-	for x in bench/samples/*.md; do echo $$x; node bench/bench.js $$x; done | \
+	for x in bench/samples/*.md; do echo $$x; node -r esm bench/bench.js $$x; done | \
 	awk -f bench/format_benchmarks.awk
 
 npm:

package-lock.json

@@ -30,7 +30,7 @@
   "scripts": {
     "build": "rollup -c",
     "lint": "eslint .",
-    "test": "node ./test/test"
+    "test": "node -r esm ./test/test"
   },
   "dependencies": {
     "entities": "~1.1.1",
@@ -44,6 +44,7 @@
     "node": "*"
   },
   "devDependencies": {
+    "esm": "^3.2.25",
     "@rollup/plugin-commonjs": "^11.0.1",
     "@rollup/plugin-node-resolve": "^7.0.0",
     "rollup-plugin-uglify": "^6.0.4",

package.json

@@ -1,9 +1,8 @@
 #!/usr/bin/env node
 "use strict";
 
-// Using commonjs here so CI can run the test file on older Node.js versions
-var fs = require("fs");
-var commonmark = require("..");
+import fs from "fs";
+import * as commonmark from "../lib/index.js";
 
 // Home made mini-version of the npm ansi module:
 var escSeq = function(s) {