demos: make run_command wait for the prompt

Most commands are non-interactive, so this reduces duplication. We can
add another function for running a command and not waiting for a
prompt when we need it.

demos/demo_git_compat.sh

@@ -6,20 +6,12 @@ parse_args "$@"
 new_tmp_dir
 
 run_demo '
-expect_prompt
 run_command "# Clone a Git repo:"
-expect_prompt
 run_command "jj git clone https://github.com/octocat/Hello-World"
-expect_prompt
 run_command "cd Hello-World"
-expect_prompt
 run_command "# Inspect it:"
-expect_prompt
 run_command "jj log"
-expect_prompt
 run_command "jj diff -r b1"
-expect_prompt
 run_command "# The repo is backed by the actual Git repo:"
-expect_prompt
 run_command "git --git-dir=.jj/store/git log --graph --all --decorate --oneline"
 '

demos/demo_helpers.tcl

@@ -8,7 +8,7 @@ proc expect_prompt {} {
 proc run_command {cmd} {
     send -h "$cmd"
     send "\r"
-    expect -timeout 1
+    expect -timeout 5 "$ "
 }
 
 proc quit_and_dump_asciicast_path {} {