pkgs.testers.testVersion

The following is the current implementation of this function.

testVersion =
    { package,
      command ? "${package.meta.mainProgram or package.pname or package.name} --version",
      version ? package.version,
    }: runCommand "${package.name}-test-version" { nativeBuildInputs = [ package ]; meta.timeout = 60; } ''
      if output=$(${command} 2>&1 | sed -e 's|${builtins.storeDir}/[^/ ]*/|{{storeDir}}/|g'); then
        if grep -Fw -- "${version}" - <<< "$output"; then
          touch $out
        else
          echo "Version string '${version}' not found!" >&2
          echo "The output was:" >&2
          echo "$output" >&2
          exit 1
        fi
      else
        echo -n ${lib.escapeShellArg command} >&2
        echo " returned a non-zero exit code." >&2
        echo "$output" >&2
        exit 1
      fi
    '';