test: increase coverage for net/blocklist

1. test new BlockList with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L34

2. test addRange with invalid start and end
https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L78

3. test blocklist addSubnet with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L81

4. test blocklist check with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L107

5. test util.inspect case
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L39

PR-URL: #36405
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>

test/parallel/test-blocklist.js

@@ -4,6 +4,7 @@ require('../common');
 
 const { BlockList } = require('net');
 const assert = require('assert');
+const util = require('util');
 
 {
   const blockList = new BlockList();
@@ -135,3 +136,45 @@ const assert = require('assert');
   assert(blockList.check('8592:757c:efaf:1fff:ffff:ffff:ffff:ffff', 'ipv6'));
   assert(!blockList.check('8592:757c:efaf:2fff:ffff:ffff:ffff:ffff', 'ipv6'));
 }
+
+{
+  assert.throws(() => new BlockList('NOT BLOCK LIST HANDLE'), /ERR_INVALID_ARG_TYPE/);
+}
+
+{
+  const blockList = new BlockList();
+  assert.throws(() => blockList.addRange('1.1.1.2', '1.1.1.1'), /ERR_INVALID_ARG_VALUE/);
+}
+
+{
+  const blockList = new BlockList();
+  assert.throws(() => blockList.addSubnet(1), /ERR_INVALID_ARG_TYPE/);
+  assert.throws(() => blockList.addSubnet('', ''), /ERR_INVALID_ARG_TYPE/);
+  assert.throws(() => blockList.addSubnet('', 1, 1), /ERR_INVALID_ARG_TYPE/);
+  assert.throws(() => blockList.addSubnet('', 1, ''), /ERR_INVALID_ARG_VALUE/);
+
+  assert.throws(() => blockList.addSubnet('', -1, 'ipv4'), /ERR_OUT_OF_RANGE/);
+  assert.throws(() => blockList.addSubnet('', 33, 'ipv4'), /ERR_OUT_OF_RANGE/);
+
+  assert.throws(() => blockList.addSubnet('', -1, 'ipv6'), /ERR_OUT_OF_RANGE/);
+  assert.throws(() => blockList.addSubnet('', 129, 'ipv6'), /ERR_OUT_OF_RANGE/);
+}
+
+{
+  const blockList = new BlockList();
+  assert.throws(() => blockList.check(1), /ERR_INVALID_ARG_TYPE/);
+  assert.throws(() => blockList.check('', 1), /ERR_INVALID_ARG_TYPE/);
+  assert.throws(() => blockList.check('', ''), /ERR_INVALID_ARG_VALUE/);
+}
+
+{
+  const blockList = new BlockList();
+  const ret = util.inspect(blockList, { depth: -1 });
+  assert.strictEqual(ret, '[BlockList]');
+}
+
+{
+  const blockList = new BlockList();
+  const ret = util.inspect(blockList, { depth: null });
+  assert(ret.includes('rules: []'));
+}