Invoke external programs using full paths

.github/workflows/test-suite.yml

@@ -18,4 +18,4 @@ jobs:
         uses: cachix/install-nix-action@v30
       - name: Run tests
         run: |
-          nix develop '.#ci' --command ./tests.bats
+          nix develop '.#ci' --command bats tests.bats nix-tests.bats

bash-env-json

@@ -22,11 +22,20 @@
 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
-VERSION="0.9.1"
+VERSION="0.9.2a"
 USAGE="bash-env-json [--help] [--shellfns <comma-separated-function-names>] [path]"
 
 shopt -s extglob
 
+# external dependencies are ideally invoked via full paths,
+# so make it straightforward for the Nix flake to substitute for these
+function _env() { env "$@"; }
+function _jq() { jq "$@"; }
+function _mktemp() { mktemp "$@"; }
+function _rm() { rm "$@"; }
+function _sed() { sed "$@"; }
+function _touch() { touch "$@"; }
+
 function capture() {
     local -n _capture_env="$1"
     local -n _capture_shellvars="$2"
@@ -37,12 +46,12 @@ function capture() {
     # environment variables
     while IFS='=' read -r -d '' _name _value; do
         _capture_env["$_name"]="${_value}"
-    done < <(env -0)
+    done < <(_env -0)
 
     # shellvars
     for _name in $(
         set -o posix
-        set | sed -n -e '/^[a-zA-Z_][a-zA-Z_0-9]*=/s/=.*$//p'
+        set | _sed -n -e '/^[a-zA-Z_][a-zA-Z_0-9]*=/s/=.*$//p'
         set +o posix
     ); do
         if test -v "$_name" -a ! "${_capture_env[$_name]+EXISTS}" -a ! "${_inhibit_shellvars[$_name]+EXISTS}"; then
@@ -52,9 +61,9 @@ function capture() {
 }
 
 function emit_value() {
-    # jq -R produces nothing on empty input, but we want ""
+    # `jq -R` produces nothing on empty input, but we want ""
     if test -n "$1"; then
-        echo -n "$1" | jq -R
+        echo -n "$1" | _jq -R
     else
         echo -n '""'
     fi
@@ -82,17 +91,17 @@ function emit_error() {
 }
 
 function emit_error_exit() {
-    emit_error "$@" | jq
+    emit_error "$@" | _jq
     exit 1
 }
 
 function emit_help_exit() {
-    emit_meta '{' '}' usage | jq
+    emit_meta '{' '}' usage | _jq
     exit 0
 }
 
 function emit_version_exit() {
-    emit_meta '{' '}' | jq
+    emit_meta '{' '}' | _jq
     exit 0
 }
 
@@ -136,11 +145,11 @@ function eval_or_source() {
     local _source _path _error_file
     _path="$1"
 
-    _error_file=$(mktemp -u)
-    touch "$_error_file"
+    _error_file=$(_mktemp -u)
+    _touch "$_error_file"
     # shellcheck disable=SC2094
     exec 3<"$_error_file" 4>"$_error_file"
-    rm -f "$_error_file"
+    _rm -f "$_error_file"
 
     if test -n "$_path"; then
         # source from file if specified
@@ -161,19 +170,19 @@ function eval_or_source() {
         if ! eval "$_source" >/dev/null 2>&4; then
             exec 4>&-
             # discard error location, because it is this file not the one sourced
-            emit_error_exit "$(sed -e 's/^.*line\s*[0-9]*:\s*//' <&3)"
+            emit_error_exit "$(_sed -e 's/^.*line\s*[0-9]*:\s*//' <&3)"
         fi
     fi
 }
 
 function invoke_safely() {
     local _fn="$1"
 
-    _error_file=$(mktemp -u)
-    touch "$_error_file"
+    _error_file=$(_mktemp -u)
+    _touch "$_error_file"
     # shellcheck disable=SC2094
     exec 3<"$_error_file" 4>"$_error_file"
-    rm -f "$_error_file"
+    _rm -f "$_error_file"
 
     "$_fn" >/dev/null 2>&4 || {
         exec 4>&-
@@ -233,14 +242,14 @@ function main() {
     capture _env_current _shellvars_current
 
     # accumulate result in a file until we know we are error-free
-    _result_file=$(mktemp -u)
-    touch "$_result_file"
+    _result_file=$(_mktemp -u)
+    _touch "$_result_file"
     # shellcheck disable=SC2094
     exec 5<"$_result_file" 6>"$_result_file"
-    rm -f "$_result_file"
+    _rm -f "$_result_file"
 
-    emit "{" env _env_previous _env_current >&6
-    emit "," shellvars _shellvars_previous _shellvars_current >&6
+    emit "{" "env" _env_previous _env_current >&6
+    emit "," "shellvars" _shellvars_previous _shellvars_current >&6
 
     test "${#_shellfn_names[@]}" -gt 0 && {
         echo ",\"fn\":{" >&6
@@ -253,8 +262,8 @@ function main() {
         capture _env_current _shellvars_current
 
         echo "$_fn_comma\"$_fn\":" >&6
-        emit "{" env _env_previous _env_current >&6
-        emit "," shellvars _shellvars_previous _shellvars_current >&6
+        emit "{" "env" _env_previous _env_current >&6
+        emit "," "shellvars" _shellvars_previous _shellvars_current >&6
         echo "}" >&6
         _fn_comma=","
     done
@@ -266,7 +275,7 @@ function main() {
     emit_meta ',' '}' >&6
     exec 6>&-
 
-    jq <&5
+    _jq <&5
 }
 
 function bad_usage() {

flake.nix

@@ -1,5 +1,5 @@
 {
-  description = "Nix package for bash-env";
+  description = "Nix package for bash-env-json";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
@@ -17,18 +17,28 @@
             let
               inherit (pkgs) bash coreutils gnused jq makeWrapper writeShellScriptBin;
               inherit (pkgs.lib) makeBinPath;
+
+              substFullPaths = program_package:
+                let replaceList = pkgs.lib.attrsets.mapAttrsToList (name: pkg: { from = " ${name} "; to = " ${pkg}/bin/${name} "; }) program_package; in
+                builtins.replaceStrings (map (x: x.from) replaceList) (map (x: x.to) replaceList);
+
             in
-            (writeShellScriptBin "bash-env-json" (builtins.readFile ./bash-env-json)).overrideAttrs (old: {
-              buildInputs = [ bash jq makeWrapper ];
+            (writeShellScriptBin "bash-env-json"
+              (substFullPaths
+                {
+                  env = pkgs.coreutils;
+                  jq = pkgs.jq;
+                  mktemp = pkgs.coreutils;
+                  rm = pkgs.coreutils;
+                  sed = pkgs.gnused;
+                  touch = pkgs.coreutils;
+                }
+                (builtins.readFile ./bash-env-json))).overrideAttrs (old: {
+              buildInputs = [ bash ];
               buildCommand =
                 ''
                   ${old.buildCommand}
                   patchShebangs $out
-                  wrapProgram $out/bin/bash-env-json --prefix PATH : ${makeBinPath [
-                    coreutils
-                    gnused
-                    jq
-                  ]}
                 '';
             });
         in

nix-tests.bats

@@ -0,0 +1,15 @@
+#!/usr/bin/env bats
+#
+# simple tests for the Nix packaging
+
+@test "simple" {
+	actual=$(echo 'export SOME_VARIABLE=some_value' | bash-env-json | jq -r '.env.SOME_VARIABLE')
+	expected='some_value'
+	test "$actual" == "$expected"
+}
+
+@test "path" {
+	actual=$(echo 'export PATH=/oops' | bash-env-json | jq -r '.env.PATH')
+	expected='/oops'
+	test "$actual" == "$expected"
+}