tests/functional: use script flags compatible with macOS

Co-authored-by: John Ericson <git@JohnEricson.me>

tests/functional/json.sh

@@ -19,6 +19,20 @@ cat > "$TEST_HOME/expected-pretty.json" <<EOF
 }
 EOF
 
+shellEscapeArray() {
+  local result=""
+  local separator=""
+
+  for item in "$@"; do
+    local escaped
+    printf -v escaped "%q" "$item"
+    result="${result}${separator}${escaped}"
+    separator=" "
+  done
+
+  echo "$result"
+}
+
 nix eval --json --expr '{ a.b.c = true; }' > "$TEST_HOME/actual.json"
 diff -U3 "$TEST_HOME/expected-machine.json" "$TEST_HOME/actual.json"
 
@@ -27,17 +41,30 @@ nix eval --json --pretty --expr \
 diff -U3 "$TEST_HOME/expected-pretty.json" "$TEST_HOME/actual.json"
 
 if type script &>/dev/null; then
-  script --return --quiet --command 'nix eval --json --expr "{ a.b.c = true; }"' > "$TEST_HOME/actual.json"
+  acceptsCommandFlag=0
+  # The macOS version just accepts multiple arguments, but util-linux and its `-c` flag only accept a single argument, which is then split on whitespace. We thus have to quote in that case.
+  if script -c true /dev/null 2>/dev/null; then
+    acceptsCommandFlag=1
+  fi
+
+  runScript() {
+    if [[ $acceptsCommandFlag -eq 0 ]]; then
+      script -e -q /dev/null "$@"
+    else
+      script -e -q /dev/null -c "$(shellEscapeArray "$@")"
+    fi
+  }
+  runScript nix eval --json --expr "{ a.b.c = true; }" > "$TEST_HOME/actual.json"
   cat "$TEST_HOME/actual.json"
   # script isn't perfectly accurate? Let's grep for a pretty good indication, as the pretty output has a space between the key and the value.
   # diff -U3 "$TEST_HOME/expected-pretty.json" "$TEST_HOME/actual.json"
   grep -F '"a": {' "$TEST_HOME/actual.json"
 
-  script --return --quiet --command 'nix eval --json --pretty --expr "{ a.b.c = true; }"' > "$TEST_HOME/actual.json"
+  runScript nix eval --json --pretty --expr "{ a.b.c = true; }" > "$TEST_HOME/actual.json"
   cat "$TEST_HOME/actual.json"
   grep -F '"a": {' "$TEST_HOME/actual.json"
 
-  script --return --quiet --command 'nix eval --json --no-pretty --expr "{ a.b.c = true; }"' > "$TEST_HOME/actual.json"
+  runScript nix eval --json --no-pretty --expr "{ a.b.c = true; }" > "$TEST_HOME/actual.json"
   cat "$TEST_HOME/actual.json"
   grep -F '"a":{' "$TEST_HOME/actual.json"
 

tests/functional/package.nix

@@ -11,6 +11,7 @@
   git,
   mercurial,
   util-linux,
+  unixtools,
 
   nix-store,
   nix-expr,
@@ -54,6 +55,7 @@ mkMesonDerivation (
         jq
         git
         mercurial
+        unixtools.script
       ]
       ++ lib.optionals stdenv.hostPlatform.isLinux [
         # For various sandboxing tests that needs a statically-linked shell,