The shflags command-line flags library creates variables at runtime
with a few well-defined functions. This causes shellcheck to spit out
lots of warnings about unassigned variables, as well as miss warnings
about unused flag variables.
We can address this with two parts:
1. Pretend that the shflags global variables are predefined like other
shell variables so that shellcheck doesn't expect users to set them.
2. Treat DEFINE_string, DEFINE_int, etc. as new commands that create
variables, similar to the existing read, local, mapfile, etc.
Part 1 can theoretically be addresssed without this by following sourced
files, but that doesn't help if people are otherwise not following
external sources.
The new behavior is on by default, similar to automatic bats test
behavior.
Addresses #1597
Always using braces makes it harder to accidentally change a variable by
pasting other text next to it, but the warning is off by default because
it's definitely a style preference. Omit special and positional
variables from the check because appending additional characters to them
already doesn't change parsing.
References of the form $var and ${var} both map to the same structure in
the AST, which prevents any later analysis functions from distinguishing
them. In preparation for adding checks that need this info, add a Bool
to T_DollarBraced that tracks whether the braces were seen at parsing
time and update all references so that this change is a no-op.
This is motivated by the fact that the popularity of bats is increasing
since the creation of bats-core/bats-core.
The code is a cherry-pick of koalaman/shellcheck/bats branch.
Fixkoalaman/shellcheck#417.
Given an input like `if [[ $(a) ]]; then ...`, this is a implicit `-n` test,
so it works like `if [[ -n $(a) ]]; then ...`. Users might confuse this for
a check for the exit code of the command a, which should be tested with:
if a; then
...
We warn the user to be more explicity and specifity the `-n`.
Fixes#1416
Vidar Holen
Benjamin Gordon
Hugo Peixoto
Virgil
Tito Sacchi
Vidar Holen
Cristian Adrián Ontivero
Gandalf-
Ng Zhi An