test: use default message for assert.strictEqual

PR-URL: #15970
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/parallel/test-zlib-from-concatenated-gzip.js

@@ -7,26 +7,27 @@ const zlib = require('zlib');
 const fs = require('fs');
 const fixtures = require('../common/fixtures');
 
-const abcEncoded = zlib.gzipSync('abc');
-const defEncoded = zlib.gzipSync('def');
+const abc = 'abc';
+const def = 'def';
+
+const abcEncoded = zlib.gzipSync(abc);
+const defEncoded = zlib.gzipSync(def);
 
 const data = Buffer.concat([
   abcEncoded,
   defEncoded
 ]);
 
-assert.strictEqual(zlib.gunzipSync(data).toString(), 'abcdef');
+assert.strictEqual(zlib.gunzipSync(data).toString(), (abc + def));
 
 zlib.gunzip(data, common.mustCall((err, result) => {
   assert.ifError(err);
-  assert.strictEqual(result.toString(), 'abcdef',
-                     'result should match original string');
+  assert.strictEqual(result.toString(), (abc + def));
 }));
 
 zlib.unzip(data, common.mustCall((err, result) => {
   assert.ifError(err);
-  assert.strictEqual(result.toString(), 'abcdef',
-                     'result should match original string');
+  assert.strictEqual(result.toString(), (abc + def));
 }));
 
 // Multi-member support does not apply to zlib inflate/deflate.
@@ -35,8 +36,7 @@ zlib.unzip(Buffer.concat([
   zlib.deflateSync('def')
 ]), common.mustCall((err, result) => {
   assert.ifError(err);
-  assert.strictEqual(result.toString(), 'abc',
-                     'result should match contents of first "member"');
+  assert.strictEqual(result.toString(), abc);
 }));
 
 // files that have the "right" magic bytes for starting a new gzip member