send-email: teach git send-email option to translate aliases

git send-email has support for converting shorthand alias names to
canonical email addresses via the alias file. It supports a wide variety
of alias file formats based on popular email program file formats.

Other programs, such as b4, would like the ability to convert aliases in
the same way as git send-email without needing to re-implement the logic
for understanding the many file formats.

Teach git send-email a new option, --translate-aliases, which will
enable this functionality. Similar to --dump-aliases, this option works
like a new mode of operation for git send-email.

When run with --translate-aliases, git send-email reads from standard
input and converts any provided alias into its canonical name and email
according to the alias file. Each expanded name and address is printed
to standard output, one per line.

Signed-off-by: Jacob Keller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jacob-keller

Documentation/git-send-email.txt

@@ -12,6 +12,7 @@ SYNOPSIS
 'git send-email' [<options>] (<file>|<directory>)...
 'git send-email' [<options>] <format-patch-options>
 'git send-email' --dump-aliases
+'git send-email' --translate-aliases
 
 
 DESCRIPTION
@@ -475,6 +476,12 @@ Information
 	that this only includes the alias name and not its expanded email addresses.
 	See 'sendemail.aliasesFile' for more information about aliases.
 
+--translate-aliases::
+	Instead of the normal operation, read from standard input and
+	interpret each line as an email alias. Translate it according to the
+	configured alias file(s). Output each translated name and email
+	address to standard output, one per line. See 'sendemail.aliasFile'
+	for more information about aliases.
 
 CONFIGURATION
 -------------

git-send-email.perl

@@ -31,6 +31,7 @@ sub usage {
 git send-email [<options>] <file|directory>
 git send-email [<options>] <format-patch options>
 git send-email --dump-aliases
+git send-email --translate-aliases
 
   Composing:
     --from                  <str>  * Email From:
@@ -99,6 +100,10 @@ sub usage {
 
   Information:
     --dump-aliases                 * Dump configured aliases and exit.
+    --translate-aliases            * Translate aliases read from standard
+                                     input according to the configured email
+                                     alias file(s), outputting the result to
+                                     standard output.
 
 EOT
 	exit(1);
@@ -212,6 +217,7 @@ sub format_2822_time {
 my $compose_filename;
 my $force = 0;
 my $dump_aliases = 0;
+my $translate_aliases = 0;
 
 # Variables to prevent short format-patch options from being captured
 # as abbreviated send-email options
@@ -476,11 +482,14 @@ sub config_regexp {
 my %dump_aliases_options = (
 	"h" => \$help,
 	"dump-aliases" => \$dump_aliases,
+	"translate-aliases" => \$translate_aliases,
 );
 $rc = GetOptions(%dump_aliases_options);
 usage() unless $rc;
 die __("--dump-aliases incompatible with other options\n")
-    if !$help and $dump_aliases and @ARGV;
+    if !$help and ($dump_aliases or $translate_aliases) and @ARGV;
+die __("--dump-aliases and --translate-aliases are mutually exclusive\n")
+    if !$help and $dump_aliases and $translate_aliases;
 my %options = (
 		    "sender|from=s" => \$sender,
 		    "in-reply-to=s" => \$initial_in_reply_to,
@@ -724,6 +733,16 @@ sub parse_sendmail_aliases {
     exit(0);
 }
 
+if ($translate_aliases) {
+	while (<STDIN>) {
+		my @addr_list = parse_address_line($_);
+		@addr_list = expand_aliases(@addr_list);
+		@addr_list = sanitize_address_list(@addr_list);
+		print "$_\n" for @addr_list;
+	}
+	exit(0);
+}
+
 # is_format_patch_arg($f) returns 0 if $f names a patch, or 1 if
 # $f is a revision list specification to be passed to format-patch.
 sub is_format_patch_arg {

t/t9001-send-email.sh

@@ -2120,6 +2120,110 @@ test_expect_success '--dump-aliases must be used alone' '
 	test_must_fail git send-email --dump-aliases [email protected] -1 refs/heads/accounting
 '
 
+test_translate_aliases () {
+	msg="$1" && shift &&
+	filetype="$1" && shift &&
+	aliases="$1" && shift &&
+	printf '%s\n' "$@" >expect &&
+	cat >.tmp-email-aliases &&
+	printf '%s\n' "$aliases" >aliases &&
+
+	test_expect_success $PREREQ "$msg" '
+		clean_fake_sendmail && rm -fr outdir &&
+		git config --replace-all sendemail.aliasesfile \
+			"$(pwd)/.tmp-email-aliases" &&
+		git config sendemail.aliasfiletype "$filetype" &&
+		git send-email --translate-aliases <aliases 2>errors >actual &&
+		test_cmp expect actual
+	'
+}
+
+test_translate_aliases '--translate-aliases sendmail format' \
+	'sendmail' \
+	'alice bcgrp' \
+	'Alice W Land <[email protected]>' \
+	'Robert Bobbyton <[email protected]>' \
+	'[email protected]' \
+	'Other <[email protected]>' <<-\EOF
+	alice: Alice W Land <[email protected]>
+	bob: Robert Bobbyton <[email protected]>
+	chloe: [email protected]
+	abgroup: alice, bob
+	bcgrp: bob, chloe, Other <[email protected]>
+	EOF
+
+test_translate_aliases '--translate-aliases mutt format' \
+	'mutt' \
+	'donald bob' \
+	'Donald C Carlton <[email protected]>' \
+	'Robert Bobbyton <[email protected]>' <<-\EOF
+	alias alice Alice W Land <[email protected]>
+	alias donald Donald C Carlton <[email protected]>
+	alias bob Robert Bobbyton <[email protected]>
+	alias chloe [email protected]
+	EOF
+
+test_translate_aliases '--translate-aliases mailrc format' \
+	'mailrc' \
+	'chloe eve alice' \
+	'[email protected]' \
+	'Eve <[email protected]>' \
+	'Alice W Land <[email protected]>' <<-\EOF
+	alias alice   "Alice W Land <[email protected]>"
+	alias eve     "Eve <[email protected]>"
+	alias bob     "Robert Bobbyton <[email protected]>"
+	alias chloe   [email protected]
+	EOF
+
+test_translate_aliases '--translate-aliases pine format' \
+	'pine' \
+	'eve bob bcgrp' \
+	'[email protected]' \
+	'[email protected]' \
+	'[email protected]' \
+	'[email protected]' \
+	'Other <[email protected]>' <<-\EOF
+	alice	Alice W Land	[email protected]		Friend
+	eve	Eve	[email protected]
+	bob	Robert Bobbyton	[email protected]
+	chloe		[email protected]
+	bcgrp		(bob, chloe, Other <[email protected]>)
+	EOF
+
+test_translate_aliases '--translate-aliases gnus format' \
+	'gnus' \
+	'alice chloe eve' \
+	'[email protected]' \
+	'[email protected]' \
+	'[email protected]' <<-\EOF
+	(define-mail-alias "alice" "[email protected]")
+	(define-mail-alias "eve" "[email protected]")
+	(define-mail-alias "bob" "[email protected]")
+	(define-mail-alias "chloe" "[email protected]")
+	EOF
+
+test_expect_success $PREREQ '--translate-aliases passes valid addresses through' '
+	cat >expect <<-\EOF &&
+	Other <[email protected]>
+	EOF
+	cat >aliases <<-\EOF &&
+	Other <[email protected]>
+	EOF
+	git send-email --translate-aliases <aliases >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success $PREREQ '--translate-aliases passes unknown aliases through' '
+	cat >expect <<-\EOF &&
+	blargh
+	EOF
+	cat >aliases <<-\EOF &&
+	blargh
+	EOF
+	git send-email --translate-aliases <aliases >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success $PREREQ 'aliases and sendemail.identity' '
 	test_must_fail git \
 		-c sendemail.identity=cloud \