Environment variables are now considered as higher-precedence than
configuration by our build system. This means that if the same value is
set in `.metamaskrc` and in an environment variable, the environment
variable is what will be used. Previously the reverse was true, the
configuration would take precedence.
It is conventional for CLI tools to consider environment variables as
higher precedence than configuration. This makes our build system less
surprising for most people.
The portfolio URL added in #15407 was meant to be configurable via
environment variable or the `.metamaskrc` file, but that configuration
was broken. Instead the default value was always used.
That configuration has been fixed. The portfolio URL can be set either
by environment variable or configuration file.
Validation has been added to the build script when the "prod" target is
selected. We now ensure that all expected environment variables are
set, and that no extra environment variables are present (which might
indicate that the wrong configuration file is being used).
The `prod` target uses a new `.metamaskprodrc` configuration file. Each
required variable can be specified either via environment variable or
via this config file. CI will continue set these via environment
variable, but for local manual builds we can use the config file to
simplify the build process and ensure consistency.
A new "dist" target has been added to preserve the ability to build a
"production-like" build without this validation.
The config validation is invoked early in the script, in the CLI
argument parsing step, so that it would fail more quickly. Otherwise
we'd have to wait a few minutes longer for the validation to run.
This required some refactoring, moving functions to the utility module
and moving the config to a dedicated module.
Additionally, support has been added for all environment variables to
be set via the config file. Previously the values `PUBNUB_PUB_KEY`,
`PUBNUB_SUB_KEY`, `SENTRY_DSN`, and `SWAPS_USE_DEV_APIS` could only be
set via environment variable. Now, all of these variables can be set
either way.
Closes#15003
