test: keeps bitcoin-cli autocomplete in sync

Adds a functional test which parses available RPC commands, generates
the associated bitcoin-cli autcomplete file and checks that the current
autocomplete matches the file
An outdated autcomplete file can be updated using the --overwrite parameter

Co-authored-by: pierrenn <git@pnn.sh>

test/functional/data/completion/bitcoin-cli.footer.bash-completion

@@ -0,0 +1,47 @@
+
+    case "$cur" in
+        -conf=*)
+            cur="${cur#*=}"
+            _filedir
+            return 0
+            ;;
+        -datadir=*)
+            cur="${cur#*=}"
+            _filedir -d
+            return 0
+            ;;
+        -*=*)	# prevent nonsense completions
+            return 0
+            ;;
+        *)
+            local helpopts commands
+
+            # only parse -help if senseful
+            if [[ -z "$cur" || "$cur" =~ ^- ]]; then
+                helpopts=$($bitcoin_cli -help 2>&1 | awk '$1 ~ /^-/ { sub(/=.*/, "="); print $1 }' )
+            fi
+
+            # only parse help if senseful
+            if [[ -z "$cur" || "$cur" =~ ^[a-z] ]]; then
+                commands=$(_bitcoin_rpc help 2>/dev/null | awk '$1 ~ /^[a-z]/ { print $1; }')
+            fi
+
+            COMPREPLY=( $( compgen -W "$helpopts $commands" -- "$cur" ) )
+
+            # Prevent space if an argument is desired
+            if [[ $COMPREPLY == *= ]]; then
+                compopt -o nospace
+            fi
+            return 0
+            ;;
+    esac
+} &&
+complete -F _bitcoin_cli bitcoin-cli
+
+# Local variables:
+# mode: shell-script
+# sh-basic-offset: 4
+# sh-indent-comment: t
+# indent-tabs-mode: nil
+# End:
+# ex: ts=4 sw=4 et filetype=sh

test/functional/data/completion/bitcoin-cli.header.bash-completion

@@ -0,0 +1,29 @@
+# Copyright (c) 2012-2024 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# call $bitcoin-cli for RPC
+_bitcoin_rpc() {
+    # determine already specified args necessary for RPC
+    local rpcargs=()
+    for i in ${COMP_LINE}; do
+        case "$i" in
+            -conf=*|-datadir=*|-regtest|-rpc*|-testnet|-testnet4)
+                rpcargs=( "${rpcargs[@]}" "$i" )
+                ;;
+        esac
+    done
+    $bitcoin_cli "${rpcargs[@]}" "$@"
+}
+
+_bitcoin_cli() {
+    local cur prev words=() cword
+    local bitcoin_cli
+
+    # save and use original argument to invoke bitcoin-cli for -help, help and RPC
+    # as bitcoin-cli might not be in $PATH
+    bitcoin_cli="$1"
+
+    COMPREPLY=()
+    _get_comp_words_by_ref -n = cur prev words cword
+

test/functional/test_runner.py

@@ -188,6 +188,7 @@
     'feature_bind_extra.py',
     'mempool_resurrect.py',
     'wallet_txn_doublespend.py --mineblock',
+    'tool_cli_bash_completion.py',
     'tool_wallet.py --legacy-wallet',
     'tool_wallet.py --legacy-wallet --bdbro',
     'tool_wallet.py --legacy-wallet --bdbro --swap-bdb-endian',

test/functional/tool_cli_bash_completion.py

@@ -0,0 +1,282 @@
+#!/usr/bin/env python3
+
+from os import path
+from collections import defaultdict
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+
+# bash cli completion file header
+COMPLETION_HEADER = """# Dynamic bash programmable completion for bitcoin-cli(1)
+#     DO NOT EDIT THIS FILE BY HAND -- THIS WILL FAIL THE FUNCTIONAL TEST tool_cli_completion
+# This file is auto-generated by the functional test tool_cli_completion.
+# If you want to modify this file, modify test/functional/tool_cli_completion.py and re-autogenerate
+# this file via the --overwrite test flag.
+
+"""
+
+# option types which are limited to certain values
+TYPED_OPTIONS = [
+        ["estimate_mode", {"UNSET", "ECONOMICAL", "CONSERVATIVE"}],
+        ["sighashtype", {"ALL", "NONE", "SINGLE", "ALL|ANYONECANPAY",
+                         "NONE|ANYONECANPAY", "SINGLE|ANYONECANPAY"}]
+]
+
+
+class PossibleArgs():
+    """ Helper class to store options associated to a command. """
+    def __init__(self, command):
+        self.command = command
+        self.arguments = {}
+
+    def set_args(self, position, values):
+        """ Set the position-th positional argument as having values as possible values. """
+        if position in self.arguments:
+            raise AssertionError(f"The positional parameter at position {position} is already defined for command '{self.command}'")
+
+        self.arguments[position] = values
+        return self
+
+    def set_bool_args(self, position):
+        return self.set_args(position, {"true", "false"})
+
+    def set_file_args(self, position):
+        # We consider an empty string as a file value for the sake of simplicity (don't
+        # have to create an extra level of indirection).
+        return self.set_args(position, {""})
+
+    def set_unknown_args(self, position):
+        return self.set_args(position, {})
+
+    def set_typed_option(self, position, arg_name):
+        """ Checks if arg_name is a typed option; if it is, sets it and return True. """
+        for option_type in TYPED_OPTIONS:
+            if arg_name == option_type[0]:
+                self.set_args(position, option_type[1])
+                return True
+        return False
+
+    def has_option(self, position):
+        return position in self.arguments and len(self.arguments[position]) > 0
+
+    def get_num_args(self):
+        """ Return the max number of positional argument the option accepts. """
+        pos = list(self.arguments.keys())
+        if len(pos) == 0:
+            return 0
+
+        return max(pos)
+
+    def generate_autocomplete(self, pos):
+        """ Generate the autocomplete file line relevent to the given position pos. """
+        if len(self.arguments[pos]) == 0:
+            raise AssertionError(f"generating undefined arg id {pos} ({self.arguments})")
+
+        # handle special file case
+        if len(self.arguments[pos]) == 1 and len(next(iter(self.arguments[pos]))) == 0:
+            return "_filedir"
+
+        # a set order is undefined, so we order args alphabetically
+        args = list(self.arguments[pos])
+        args.sort()
+
+        return "COMPREPLY=( $( compgen -W \"" + ' '.join(args) + "\" -- \"$cur\" ) )"
+
+# commands where the option type can only be difficultly derived from the help message
+SPECIAL_OPTIONS = [
+        PossibleArgs("addnode").set_args(2, {"add", "remove", "onetry"}),
+        PossibleArgs("setban").set_args(2, {"add", "remove"}),
+]
+
+
+def generate_start_complete(cword):
+    """ Generate the start of an autocomplete block (beware of indentation). """
+    if cword > 1:
+        return f"""    if ((cword > {cword})); then
+        case ${{words[cword-{cword}]}} in"""
+
+    return "    case \"$prev\" in"
+
+
+def generate_end_complete(cword):
+    """ Generate the end of an autocomplete block. """
+    if cword > 1:
+        return f"\n{' ' * 8}esac\n{' ' * 4}fi\n\n"
+
+    return f"\n{' ' * 4}esac\n"
+
+
+class CliCompletionTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_cli()
+        # self.skip_if_no_wallet()
+        self.skip_if_no_bitcoind_zmq()
+
+    def add_options(self, parser):
+        parser.add_argument(
+                '--header',
+                help='Static header part of the bash completion file',
+        )
+
+        parser.add_argument(
+                '--footer',
+                help='Static footer part of the bash completion file',
+        )
+
+        parser.add_argument(
+                '--completion',
+                help='Location of the current bash completion file',
+        )
+
+        parser.add_argument(
+                '--overwrite',
+                default=False,
+                action='store_true',
+                help='Force the test to overwrite the file pointer to by the --completion'
+                    'to the newly generated completion file',
+        )
+    def parse_single_helper(self, option):
+        """ Complete the arguments of option via the RPC format command. """
+
+        res = self.nodes[0].format(command=option.command, output='args_cli')
+        if len(res) == 0:
+            return option
+
+        if res.count('\n') > 1:
+            raise AssertionError(
+                f"command {option.command} doesn't support format RPC. Should it be a hidden command? "
+                f"Please call RPCHelpMan::Check when adding a new non-hidden command. Returned: {res}"
+            )
+
+        for idx, argument in enumerate(res.split(",")):
+            elems = argument.split(":")
+
+            if option.set_typed_option(idx+1, elems[0]):
+                continue
+
+            if elems[1] == "boolean":
+                option.set_bool_args(idx+1)
+                continue
+
+            if elems[1] == "file":
+                option.set_file_args(idx+1)
+                continue
+
+            if not option.has_option(idx+1):
+                option.set_unknown_args(idx+1)
+
+        return option
+
+    def get_command_options(self, command):
+        """ Returns the corresponding PossibleArgs for the command. """
+
+        # verify it's not a special option first
+        for soption in SPECIAL_OPTIONS:
+            if command == soption.command:
+                return self.parse_single_helper(soption)
+
+        return self.parse_single_helper(PossibleArgs(command))
+
+    def generate_completion_block(self, options):
+        commands = [o.command for o in options]
+        self.log.info(f"Generating part of the completion file for options {commands}")
+
+        if len(options) == 0:
+            return ""
+
+        generated = ""
+        max_pos_options = max(options, key=lambda o: o.get_num_args()).get_num_args()
+        for cword in range(max_pos_options, 0, -1):
+            this_options = [option for option in options if option.has_option(cword)]
+            if len(this_options) == 0:
+                continue
+
+            # group options by their arguments value
+            grouped_options = defaultdict(list)
+            for option in this_options:
+                arg = option.generate_autocomplete(cword)
+                grouped_options[arg].append(option)
+
+            # generate the cword block
+            indent = 12 if cword > 1 else 8
+            generated += generate_start_complete(cword)
+            for line, opt_gr in grouped_options.items():
+                opt_gr.sort(key=lambda o: o.command)  # show options alphabetically for clarity
+                args = '|'.join([o.command for o in opt_gr])
+                generated += f"\n{' '*indent}{args})\n"
+                generated += f"{' ' * (indent + 4)}{line}\n{' ' * (indent + 4)}return 0\n{' ' * (indent + 4)};;"
+            generated += generate_end_complete(cword)
+
+        return generated
+
+    def generate_completion_file(self, commands):
+        try:
+            with open(self.options.header, 'r', encoding='utf-8') as header_file:
+                header = header_file.read()
+
+            with open(self.options.footer, 'r', encoding='utf-8') as footer_file:
+                footer = footer_file.read()
+        except Exception as e:
+            raise AssertionError(
+                        f"Could not read header/footer ({self.options.header} and {self.options.footer}) files. "
+                        f"Tell the test where to find them using the --header/--footer parameters ({e})."
+            )
+        return COMPLETION_HEADER + header + commands + footer
+
+    def write_completion_file(self, new_file):
+        try:
+            with open(self.options.completion, 'w', encoding='utf-8') as completion_file:
+                completion_file.write(new_file)
+        except Exception as e:
+            raise AssertionError(
+                        f"Could not write the autocomplete file to {self.options.completion}. "
+                        f"Tell the test where to find it using the --completion parameters ({e})."
+            )
+
+    def read_completion_file(self):
+        try:
+            with open(self.options.completion, 'r', encoding='utf-8') as completion_file:
+                return completion_file.read()
+        except Exception as e:
+            raise AssertionError(
+                        f"Could not read the autocomplete file ({self.options.completion}) file. "
+                        f"Tell the test where to find it using the --completion parameters ({e})."
+            )
+
+
+    def run_test(self):
+        # self.config is not available in self.add_options, so complete filepaths here
+        src_dir = self.config["environment"]["SRCDIR"]
+        test_data_dir = path.join(src_dir, 'test', 'functional', 'data', 'completion')
+        if self.options.header is None or len(self.options.header) == 0:
+            self.options.header = path.join(test_data_dir, 'bitcoin-cli.header.bash-completion')
+
+        if self.options.footer is None or len(self.options.footer) == 0:
+            self.options.footer = path.join(test_data_dir, 'bitcoin-cli.footer.bash-completion')
+
+        if self.options.completion is None or len(self.option.completion) == 0:
+            self.options.completion = path.join(src_dir, 'contrib', 'completions', 'bash', 'bitcoin-cli.bash')
+
+        self.log.info('Parsing help commands to get all the command arguments...')
+        commands = self.nodes[0].help().split("\n")
+        commands = [c.split(' ')[0] for c in commands if not c.startswith("== ") and len(c) > 0]
+        commands = [self.get_command_options(c) for c in commands]
+
+        self.log.info('Generating new autocompletion file...')
+        commands = self.generate_completion_block(commands)
+        new_completion = self.generate_completion_file(commands)
+
+        if self.options.overwrite:
+            self.log.info("Overwriting the completion file...")
+            self.write_completion_file(new_completion)
+
+        self.log.info('Checking if the generated and the original completion files matches...')
+        completion = self.read_completion_file()
+        assert_equal(new_completion, completion)
+
+if __name__ == '__main__':
+    CliCompletionTest(__file__).main()