linting: add shelcheck for shell script lint

Add linting for shell scripts in the scipts directory as well as any
*.sh file accross the project using shellcheck.

Signed-off-by: Andreas Hatziiliou <andreas.hatziiliou@savoirfairelinux.com>

Author: L-series

nix/util.nix

@@ -86,7 +86,8 @@ rec {
 
       inherit (pkgs)
         nixpkgs-fmt
-        shfmt;
+        shfmt
+        shellcheck;
 
       inherit (pkgs.python3Packages)
         mpmath sympy black pyparsing pyyaml;

scripts/format

@@ -41,7 +41,11 @@ if ! command -v shfmt 2>&1 >/dev/null; then
   error "shfmt not found. Are you running in a nix shell? See BUILDING.md."
   exit 1
 fi
-shfmt -s -w -l -i 2 -ci -fn $(shfmt -f $(git grep -l '' :/))
+
+# Find all scripts in the repo
+ALL_FILES=$(git grep -l '' :/)
+SHELL_SCRIPTS=$(echo "$ALL_FILES" | xargs shfmt -f)
+shfmt -s -l -i 2 -ci -fn $SHELL_SCRIPTS
 
 info "Formatting python scripts"
 if ! command -v black 2>&1 >/dev/null; then

scripts/lint

@@ -106,15 +106,36 @@ gh_error_simple()
   fi
 }
 
+run-shellcheck()
+{
+  if ! command -v shellcheck >/dev/null; then
+    gh_error_simple "Shellcheck missing" "shellcheck is not installed"
+    error "Lint shellcheck"
+    SUCCESS=false
+    gh_summary_failure "Lint shellcheck"
+    return 0
+  fi
+
+  checkerr "Lint shellcheck" "$(shellcheck --severity=warning $SHELL_SCRIPTS)"
+}
+
 # Formatting
 SUCCESS=true
 
+# Get list of shell scripts for linting
+ALL_FILES=$(git grep -l '' :/)
+SHELL_SCRIPTS=$(echo "$ALL_FILES" | xargs shfmt -f)
+
 gh_group_start "Linting nix files with nixpkgs-fmt"
 checkerr "Lint nix" "$(nixpkgs-fmt --check "$ROOT")"
 gh_group_end
 
 gh_group_start "Linting shell scripts with shfmt"
-checkerr "Lint shell" "$(shfmt -s -l -i 2 -ci -fn $(shfmt -f $(git grep -l '' :/)))"
+checkerr "Lint shell" "$(echo $SHELL_SCRIPTS | xargs shfmt -s -l -i 2 -ci -fn)"
+gh_group_end
+
+gh_group_start "Linting shell scripts with shellcheck"
+run-shellcheck
 gh_group_end
 
 gh_group_start "Linting python scripts with black"