tests: Switch from unbuffer to ptyx

unbuffer is part of expect, which is not actively maintained.  This
recently led to a CI failure on NetBSD which looked like

    can't find package Expect
        while executing
    "package require Expect"
        (file "/usr/pkg/bin/unbuffer" line 6)

Rather than debug this, I just reimplemented unbuffer myself.  This also
reduces our test dependencies, which is nice.

Link: https://sourceforge.net/p/expect/bugs/107/
Link: https://github.com/tavianator/bfs/actions/runs/14421150823/job/40444068385

Author: tavianator

.github/workflows/ci.yml

@@ -16,7 +16,6 @@ jobs:
           sudo dpkg --add-architecture i386
           sudo apt-get update -y
           sudo apt-get install -y \
-              expect \
               mandoc \
               gcc-multilib \
               libgcc-s1:i386 \
@@ -57,7 +56,6 @@ jobs:
         run: |
           sudo apt-get update -y
           sudo apt-get install -y \
-              expect \
               mandoc \
               acl \
               libacl1-dev \
@@ -110,10 +108,8 @@ jobs:
           run: |
             sudo pkg install -y \
                 bash \
-                expect \
                 oniguruma \
-                pkgconf \
-                tcl-wrapper
+                pkgconf
             sudo mount -t fdescfs none /dev/fd
             .github/diag.sh make -j$(nproc) distcheck
 
@@ -139,7 +135,6 @@ jobs:
           run: |
             sudo pkg_add \
                 bash \
-                expect \
                 gmake \
                 oniguruma
             jobs=$(sysctl -n hw.ncpu)
@@ -170,8 +165,7 @@ jobs:
             sudo pkgin -y install \
                 bash \
                 oniguruma \
-                pkgconf \
-                tcl-expect
+                pkgconf
             jobs=$(sysctl -n hw.ncpu)
             ./configure
             .github/diag.sh make -j$jobs check TEST_FLAGS="--sudo --verbose=skipped"
@@ -198,11 +192,9 @@ jobs:
           prepare: |
             pkg install -y \
                 bash \
-                expect \
                 oniguruma \
                 pkgconf \
-                sudo \
-                tcl-wrapper
+                sudo
             pw useradd -n action -m -G wheel -s /usr/local/bin/bash
             echo "%wheel ALL=(ALL) NOPASSWD: ALL" >>/usr/local/etc/sudoers
 
@@ -235,7 +227,6 @@ jobs:
             pkg install \
                 bash \
                 build-essential \
-                expect \
                 gnu-make \
                 onig \
                 sudo

.github/workflows/codecov.yml

@@ -13,7 +13,6 @@ jobs:
         run: |
           sudo apt-get update -y
           sudo apt-get install -y \
-              expect \
               gcc \
               acl \
               libacl1-dev \

tests/run.sh

@@ -362,20 +362,12 @@ invoke_bfs() {
     fi
 }
 
-if command -v unbuffer &>/dev/null; then
-    UNBUFFER=unbuffer
-elif command -v expect_unbuffer &>/dev/null; then
-    UNBUFFER=expect_unbuffer
-fi
-
 # Run bfs with a pseudo-terminal attached
 bfs_pty() {
-    test -n "${UNBUFFER:-}" || skip
-
     bfs_verbose "$@"
 
     local ret=0
-    "$UNBUFFER" bash -c 'stty cols 80 rows 24 && "$@" </dev/null' bash "${BFS[@]}" "$@" || ret=$?
+    "$PTYX" -w80 -h24 -- "${BFS[@]}" "$@" || ret=$?
 
     if ((ret > 125)); then
         exit $ret

tests/util.sh

@@ -16,6 +16,7 @@ ROOT=$(_realpath "$(dirname -- "$TESTS")")
 TESTS="$ROOT/tests"
 BIN="$ROOT/bin"
 MKSOCK="$BIN/tests/mksock"
+PTYX="$BIN/tests/ptyx"
 XTOUCH="$BIN/tests/xtouch"
 UNAME=$(uname)