[test/spec] New file for bash-specific trap features

spec/builtin-trap-bash.test.sh

@@ -0,0 +1,263 @@
+# builtin-trap-bash.test.sh
+
+#### trap -l
+trap -l | grep INT >/dev/null
+## status: 0
+
+
+#### trap -p
+
+trap 'echo exit' EXIT
+# debug trap also remains on
+#trap 'echo debug' DEBUG
+
+trap -p > parent.txt
+
+trap -p | cat > child.txt
+
+grep EXIT parent.txt >/dev/null
+echo status=$?
+
+grep EXIT child.txt >/dev/null
+echo status=$?
+
+#grep DEBUG parent.txt >/dev/null
+#echo status=$?
+
+#grep DEBUG child.txt >/dev/null
+#echo status=$?
+
+## STDOUT:
+status=0
+status=0
+exit
+## END
+
+#### trap DEBUG
+case $SH in (dash|mksh) exit ;; esac
+
+debuglog() {
+  echo "  [$@]"
+}
+trap 'debuglog $LINENO' DEBUG
+
+echo a
+echo b; echo c
+
+echo d && echo e
+echo f || echo g
+
+(( h = 42 ))
+[[ j == j ]]
+
+## STDOUT:
+  [8]
+a
+  [9]
+b
+  [9]
+c
+  [11]
+d
+  [11]
+e
+  [12]
+f
+  [14]
+  [15]
+## END
+
+#### trap DEBUG and command sub / subshell
+case $SH in (dash|mksh) exit ;; esac
+
+debuglog() {
+  echo "  [$@]"
+}
+trap 'debuglog $LINENO' DEBUG
+
+echo "result =" $(echo command sub)
+( echo subshell )
+echo done
+
+## STDOUT:
+  [8]
+result = command sub
+subshell
+  [10]
+done
+## END
+
+#### trap DEBUG and pipeline
+case $SH in (dash|mksh) exit 1 ;; esac
+
+debuglog() {
+  echo "  [$@]"
+}
+trap 'debuglog $LINENO' DEBUG
+
+# gets run for each one of these
+{ echo a; echo b; }
+
+# only run for the last one, maybe I guess because traps aren't inherited?
+{ echo x; echo y; } | wc -l
+
+# gets run for both of these
+date | wc -l
+
+date |
+  wc -l
+
+## STDOUT:
+  [8]
+a
+  [8]
+b
+  [10]
+2
+  [12]
+  [12]
+1
+  [14]
+  [15]
+1
+## END
+
+
+#### trap DEBUG with compound commands
+case $SH in (dash|mksh) exit 1 ;; esac
+
+# I'm not sure if the observed behavior actually matches the bash documentation
+# ...
+#
+# https://www.gnu.org/software/bash/manual/html_node/Bourne-Shell-Builtins.html#Bourne-Shell-Builtins
+#
+# "If a sigspec is DEBUG, the command arg is executed before every simple 
+# command, for command, case command, select command, every arithmetic for
+# command, and before the first command executes in a shell function."
+
+debuglog() {
+  echo "  [$@]"
+}
+trap 'debuglog $LINENO' DEBUG
+
+f() {
+  local mylocal=1
+  for i in "$@"; do
+    export i=$i
+  done
+}
+
+echo '-- assign --'
+g=1   # executes ONCE here
+
+echo '-- function call --'
+f A B C  # executes ONCE here, but does NOT go into th efunction call
+
+
+echo '-- for --'
+# why does it execute twice here?  because of the for loop?  That's not a
+# simple command.
+for i in 1 2; do
+  echo for1 $i
+  echo for2 $i
+done
+
+echo '-- while --'
+i=0
+while (( i < 2 )); do
+  echo while1 
+  echo while2
+  (( i++ ))
+done
+
+echo '-- if --'
+if true; then
+  echo IF
+fi
+
+echo '-- case --'
+case x in
+  (x)
+    echo CASE
+esac
+
+## STDOUT:
+  [16]
+-- assign --
+  [17]
+  [19]
+-- function call --
+  [20]
+  [23]
+-- for --
+  [24]
+  [25]
+for1 1
+  [26]
+for2 1
+  [24]
+  [25]
+for1 2
+  [26]
+for2 2
+  [29]
+-- while --
+  [30]
+  [31]
+  [32]
+while1
+  [33]
+while2
+  [34]
+  [31]
+  [32]
+while1
+  [33]
+while2
+  [34]
+  [31]
+  [37]
+-- if --
+  [38]
+  [39]
+IF
+  [42]
+-- case --
+  [43]
+  [45]
+CASE
+## END
+
+
+#### trap RETURN
+profile() {
+  echo "profile [$@]"
+}
+g() {
+  echo --
+  echo g
+  echo --
+  return
+}
+f() {
+  echo --
+  echo f
+  echo --
+  g
+}
+# RETURN trap doesn't fire when a function returns, only when a script returns?
+# That's not what the manual syas.
+trap 'profile x y' RETURN
+f
+. $REPO_ROOT/spec/testdata/return-helper.sh
+## status: 42
+## STDOUT:
+--
+f
+--
+--
+g
+--
+return-helper.sh
+profile [x y]
+## END