[Fix]: Fix NodeJS download link for armv8l

[dewren99]

Fixes #3035. Fixes #2845.

I wasn't sure what would be the best solution. Right now, if NVM_ARCH is armv8l, it falls back to armv7l since ARMv8 is backward compatible with ARMv7.

I think other approaches are

• Changing aarch64) NVM_ARCH="arm64" ;; pattern to aarch64 | armv8l) NVM_ARCH="arm64" ;;. That way it would step into the following code block and also fall back to armv7l.

  # If running a 64bit ARM kernel but a 32bit ARM userland,
  # change ARCH to 32bit ARM (armv7l) if /sbin/init is 32bit executable
  if [ "$(uname)" = "Linux" ] \
    && ( [ "${NVM_ARCH}" = arm64 ] || [ "${NVM_ARCH}" = armv8l ] ) \
    && [ "$(command od -An -t x1 -j 4 -N 1 "/sbin/init" 2>/dev/null)" = ' 01' ]\
  ; then
    NVM_ARCH=armv7l
    HOST_ARCH=armv7l
  fi

• Instead of falling back to armv7l, create another if block to use arm64, something like

  if [ "$(uname)" = "Linux" ] \
    && [ "${NVM_ARCH}" = armv8l ] \
  ; then
    NVM_ARCH=arm64
    HOST_ARCH=arm64
  fi

Please let me know if you have any suggestions, feedback, or concerns!

[ljharb]

I'd love a regression test - even a unit test that mocks out the arch - that can illustrate what this is fixing :-)

[dewren99]

Thanks for the suggestion, that was helpful!
I added a mock for the armv8l arch. With the current change, it should behave as if the arch was armv7l.

[ljharb]

The mock is good, but we'd also need a test in test/fast/Unit tests/nvm_get_arch that exercises it. I'll see if i can add one.