mu-init: guess maildir when --maildir is missing

Re-instate the guessing that's in the manpage. Add unit tests.
Update documentation.

Fixes #2616.

lib/utils/mu-utils-file.hh

@@ -35,12 +35,12 @@ namespace Mu {
  * Check if the directory has the given attributes
  *
  * @param path path to dir
- * @param readable is it readable?
- * @param writeable is it writable?
+ * @param readable is it readable? false means "don't care"
+ * @param writeable is it writable? false means "don't care"
  *
  * @return true if is is a directory with given attributes; false otherwise.
  */
-bool check_dir(const std::string& path, bool readable, bool writeable);
+bool check_dir(const std::string& path, bool readable=false, bool writeable=false);
 
 /**
  * See g_canonicalize_filename
@@ -233,8 +233,9 @@ Result<void> remove_directory(const std::string& path);
  * @param try_setsid whether to try setsid(2) (see its manpage for details) if this
  *        system supports it.
  *
- * @return Ok(exit code) or an error. Note that exit-code != 0 is _not_ considered an error from the
- * perspective of run_command, but is for run_command0
+ * @return Ok(exit code) or an error. Note that exit-code != 0 is _not_
+ * considered an error from the perspective of run_command, but is for
+ * run_command0
  */
 struct CommandOutput {
 	int exit_code;

man/mu-init.1.org

@@ -18,9 +18,11 @@ has completed, you can run *mu index*
 
 ** -m, --maildir=<maildir>
 
-starts searching at =<maildir>=. By default, *mu* uses whatever the *MAILDIR*
-environment variable is set to; if it is not set, it tries =~/Maildir= if it
-already exists.
+use =<maildir>= as the root-maildir.
+
+By default, *mu* uses the *MAILDIR* environment; if it is not set, it uses =~/Maildir=
+if it is an existing directory. If neither of those can be used, the ~--maildir~
+option is required.
 
 ** --my-address=<email-address-or-regex>
 
@@ -37,8 +39,8 @@ argument may need to be quoted.
 
 ** --ignored-address=<email-address-or-regex>
 
-specifies that some e-mail address is to be ignored from the contacts-cache
-(the option can be used multiple times). Such address then cannot be found with
+specifies that some e-mail address is to be ignored from the contacts-cache (the
+option can be used multiple times). Such addresses then cannot be found with
 *mu-cfind(1)* or in the Mu4e contacts cache.
 
 =<my-email-address>= can be either a plain e-mail address or a regexp, just like
@@ -51,9 +53,9 @@ specifies the maximum size for an e-mail message. Usually, the default of
 
 ** --batch-size=<size>
 
-number of changes after which they are committed to the database; decreasing
-this reduces the memory requirements, but make indexing substantially slows (and
-vice-versa for increasing). Usually, the default of 250000 should be fine.
+the number of changes after which they are committed to the database; decreasing
+the value reduces the memory requirements, at the cost of make indexing
+substantially slower. Usually, the default of 250000 should be fine.
 
 Batch-size 0 is interpreted as 'use the default'.
 
@@ -61,7 +63,7 @@ Batch-size 0 is interpreted as 'use the default'.
 
 whether to enable support for using ngrams in indexing and query parsing; this
 can be useful for languages without explicit word breaks, such as
-Chinese/Japanese/Korean. See *NGRAM SUPPORT* below.
+Chinese/Japanese/Korean. See *NGRAM SUPPORT* below for details.
 
 ** --reinit
 
@@ -75,9 +77,9 @@ options.
 
 *mu*'s underlying Xapian database supports 'ngrams', which improve searching for
 languages/scripts that do not have explicit word breaks, such as Chinese,
-Japanese and Korean. It is fairly intrusive, and influence both indexing and
+Japanese and Korean. It is fairly intrusive, and influences both indexing and
 query-parsing; it is not enabled by default, and is recommended only if you need
-to search in such languages.
+to search for messages written in such languages.
 
 When enabled, *mu* automatically uses ngrams automatically. Xapian environment
 variables such as ~XAPIAN_CJK_NGRAM~ are ignored.

mu/meson.build

@@ -77,6 +77,13 @@ test('test-cmd-index',
                 cpp_args: ['-DBUILD_TESTS'],
                 dependencies: [glib_dep, lib_mu_dep]))
 
+test('test-cmd-init',
+     executable('test-cmd-init',
+                'mu-cmd-init.cc',
+                install: false,
+                cpp_args: ['-DBUILD_TESTS'],
+                dependencies: [glib_dep, lib_mu_dep]))
+
 test('test-cmd-mkdir',
      executable('test-cmd-mkdir',
                 'mu-cmd-mkdir.cc',
@@ -105,7 +112,6 @@ test('test-cmd-verify',
                 cpp_args: ['-DBUILD_TESTS'],
                 dependencies: [glib_dep, lib_mu_dep]))
 
-
 test('test-cmd-view',
      executable('test-cmd-view',
                 'mu-cmd-view.cc',

mu/mu-cmd-index.cc

@@ -152,11 +152,11 @@ test_mu_index(size_t batch_size=0)
 	auto res1 = run_command({MU_PROGRAM, "--quiet", "init", "--batch-size",
 			mu_format("{}", batch_size == 0 ? 10000 : batch_size),
 			"--muhome", mu_home, "--maildir" , MU_TESTMAILDIR2});
-	assert_valid_result(res1);
+	assert_valid_command(res1);
 
 	auto res2 = run_command({MU_PROGRAM, "--quiet", "index",
 			"--muhome", mu_home});
-	assert_valid_result(res2);
+	assert_valid_command(res2);
 
 	auto&& store = unwrap(Store::make(join_paths(temp_dir.path(), "xapian")));
 	g_assert_cmpuint(store.size(),==,14);

mu/mu-cmd-init.cc

@@ -23,6 +23,8 @@
 
 using namespace Mu;
 
+#ifndef BUILD_TESTS
+
 Result<void>
 Mu::mu_cmd_init(const Options& opts)
 {
@@ -79,3 +81,61 @@ Mu::mu_cmd_init(const Options& opts)
 
 	return Ok();
 }
+
+
+
+#else /* BUILD_TESTS */
+
+/*
+ * Tests.
+ *
+ */
+#include <config.h>
+#include <mu-store.hh>
+#include "utils/mu-test-utils.hh"
+
+
+static void
+test_mu_init_basic()
+{
+	TempDir temp_dir{};
+
+	const auto mu_home{temp_dir.path()};
+
+	auto res1 = run_command({MU_PROGRAM, "--quiet", "init",
+			"--muhome", mu_home, "--maildir" , MU_TESTMAILDIR2});
+	assert_valid_command(res1);
+
+	auto&& store = unwrap(Store::make(join_paths(temp_dir.path(), "xapian")));
+	g_assert_true(store.empty());
+}
+
+static void
+test_mu_init_maildir()
+{
+	TempDir temp_dir{};
+
+	const auto mu_home{temp_dir.path()};
+
+	g_setenv("MAILDIR", MU_TESTMAILDIR2, 1);
+	auto res1 = run_command({MU_PROGRAM, "--quiet", "init",
+			"--muhome", mu_home});
+	assert_valid_command(res1);
+
+	auto&& store = unwrap(Store::make(join_paths(temp_dir.path(), "xapian")));
+	g_assert_true(store.empty());
+	assert_equal(store.root_maildir(), MU_TESTMAILDIR2);
+}
+
+int
+main(int argc, char* argv[])
+{
+	mu_test_init(&argc, &argv);
+
+	g_test_add_func("/cmd/init/basic", test_mu_init_basic);
+	g_test_add_func("/cmd/init/maildir", test_mu_init_maildir);
+
+	return g_test_run();
+}
+
+#endif /*BUILD_TESTS*/

mu/mu-options.cc

@@ -184,20 +184,16 @@ options_map(const IE& ie)
 	return map;
 }
 
-
-
 // transformers
 
-
 // Expand the path using wordexp
 static const std::function ExpandPath = [](std::string filepath)->std::string {
 	if (auto&& res{expand_path(filepath)}; !res)
 		throw CLI::ValidationError{res.error().what()};
 	else
-		return filepath = std::move(res.value());
+		return res.value();
 };
 
-
 // Canonicalize path
 static const std::function CanonicalizePath = [](std::string filepath)->std::string {
 	return filepath = canonicalize_filename(filepath);
@@ -289,7 +285,7 @@ sub_extract(CLI::App& sub, Options& opts)
 	sub.add_option("--target-dir", opts.extract.targetdir,
 		       "Target directory for saving")
 		->type_name("<dir>")
-		->transform(ExpandPath, "expand path")
+		->transform(ExpandPath, "expand target path")
 		->default_str("<current>")
 		->default_val(".");
 	sub.add_flag("--uncooked,-u", opts.extract.uncooked,
@@ -403,7 +399,7 @@ sub_find(CLI::App& sub, Options& opts)
 	sub.add_option("--linksdir", opts.find.linksdir,
 		       "Use bookmarked query")
 		->type_name("<dir>")
-		->transform(ExpandPath, "expand path");
+		->transform(ExpandPath, "expand linksdir path");
 
 	sub.add_option("--summary-len", opts.find.summary_len,
 		       "Use up to so many lines for the summary")
@@ -448,10 +444,20 @@ sub_info(CLI::App& sub, Options& opts)
 static void
 sub_init(CLI::App& sub, Options& opts)
 {
-	sub.add_option("--maildir,-m", opts.init.maildir,
-		       "Top of the maildir")
+	const auto default_mdir = std::invoke([]()->std::string {
+		if (const auto mdir_env{::getenv("MAILDIR")}; mdir_env)
+			return mdir_env;
+		else if (const auto mdir_home = ::join_paths(g_get_home_dir(), "Maildir");
+			 check_dir(mdir_home))
+			return mdir_home;
+		else
+			return {};
+	});
+
+	sub.add_option("--maildir,-m", opts.init.maildir, "Top of the maildir")
 		->type_name("<maildir>")
-		->transform(ExpandPath, "expand path");
+		->default_val(default_mdir)
+		->transform(ExpandPath, "expand maildir path");
 	sub.add_option("--my-address", opts.init.my_addresses,
 		       "Personal e-mail address or regexp")
 		->type_name("<address>");
@@ -503,8 +509,8 @@ sub_move(CLI::App& sub, Options& opts)
 
 	sub.add_option("source", opts.move.src, "Message file to move")
 		->type_name("<message-path>")
-		->transform(ExpandPath, "expand path")
-		->transform(CanonicalizePath, "canonicalize path")
+		->transform(ExpandPath, "expand source path")
+		->transform(CanonicalizePath, "canonicalize source path")
 		->required();
 	sub.add_option("destination", opts.move.dest,
 		       "Destination maildir")
@@ -813,7 +819,7 @@ There is NO WARRANTY, to the extent permitted by law.
 					opts.muhome, "Specify alternative mu directory")
 				->envname("MUHOME")
 				->type_name("<dir>")
-				->transform(ExpandPath, "expand path");
+				->transform(ExpandPath, "expand muhome path");
 	}
 
 	/* add scripts (if supported) as semi-subcommands as well */