test: isolate styleText tests from the environment

The TTY cases inherit TERM, CI and the color override variables. These
can disable colors in a case expecting styling, or force colors in a
case expecting plain text. The tests skip these cases without a TTY,
which hides the dependency in many standalone runs.

Set a color-capable TERM and only the environment variables specified
by each case. Remove the RISC-V flaky expectations.

Refs: nodejs/build#4099 (comment)
Signed-off-by: Filip Skokan <panva.ip@gmail.com>
Assisted-by: Claude, Codex
PR-URL: #66320
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: panva

test/parallel/parallel.status

@@ -130,8 +130,3 @@ test-http-correct-hostname: SKIP
 [$arch==riscv64]
 # Snapshot test works in some environments but not others for now on RISC-V
 test-snapshot-reproducible: PASS, FLAKY
-# styletext ones are failing in jenkins but pass standalone so something
-# odd is happening to the ttys when run via java. tty issue
-# https://github.com/nodejs/build/issues/4099#issuecomment-5070947806
-test-util-styletext: PASS, FLAKY
-test-util-styletext-hex: PASS, FLAKY

test/parallel/test-util-styletext-hex.js

@@ -213,8 +213,10 @@ describe('util.styleText hex color support', () => {
       for (const testCase of testCases) {
         it(`should respect ${testCase.description}`, () => {
           writeStream.isTTY = testCase.isTTY;
+          // Do not inherit color-related variables (TERM, CI, NO_COLOR, ...)
+          // from the environment the test happens to run in.
           process.env = {
-            ...originalEnv,
+            TERM: 'xterm-256color',
             ...testCase.env,
           };
           const output = util.styleText('#ffcc00', 'test', { stream: writeStream });

test/parallel/test-util-styletext.js

@@ -203,9 +203,11 @@ if (fd !== -1) {
     { isTTY: true, env: { FORCE_COLOR: '1', NO_COLOR: '1', NODE_DISABLE_COLORS: '1' }, expected: styled },
   ].forEach((testCase) => {
     writeStream.isTTY = testCase.isTTY;
+    // Do not inherit color-related variables (TERM, CI, NO_COLOR, ...) from
+    // the environment the test happens to run in.
     process.env = {
-      ...process.env,
-      ...testCase.env
+      TERM: 'xterm-256color',
+      ...testCase.env,
     };
     {
       const output = util.styleText('red', 'test', { stream: writeStream });