[PATCH v8 3/7] progress.c tests: make start/stop commands on stdin

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the usage of the "test-tool progress" introduced in
2bb74b53a49 (Test the progress display, 2019-09-16) to take command
like "start" and "stop" on stdin, instead of running them implicitly.

This makes for tests that are easier to read, since the recipe will
mirror the API usage, and allows for easily testing invalid usage that
would yield (or should yield) a BUG(), e.g. providing two "start"
calls in a row. A subsequent commit will add such tests.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/helper/test-progress.c    | 46 ++++++++++++++++++++++-------
 t/t0500-progress-display.sh | 58 +++++++++++++++++++++++--------------
 2 files changed, 72 insertions(+), 32 deletions(-)

diff --git a/t/helper/test-progress.c b/t/helper/test-progress.c
index 50fd3be3dad..becc163375f 100644
--- a/t/helper/test-progress.c
+++ b/t/helper/test-progress.c
@@ -3,6 +3,9 @@
  *
  * Reads instructions from standard input, one instruction per line:
  *
+ *   "start <total>[ <title>]" - Call start_progress(title, total),
+ *                               Uses the default title of "Working hard"
+ *                               if the " <title>" is omitted.
  *   "progress <items>" - Call display_progress() with the given item count
  *                        as parameter.
  *   "throughput <bytes> <millis> - Call display_throughput() with the given
@@ -10,6 +13,7 @@
  *                                  specify the time elapsed since the
  *                                  start_progress() call.
  *   "update" - Set the 'progress_update' flag.
+ *   "stop" - Call stop_progress().
  *
  * See 't0500-progress-display.sh' for examples.
  */
@@ -19,34 +23,52 @@
 #include "parse-options.h"
 #include "progress.h"
 #include "strbuf.h"
+#include "string-list.h"
 
 int cmd__progress(int argc, const char **argv)
 {
-	int total = 0;
-	const char *title;
+	const char *const default_title = "Working hard";
+	struct string_list titles = STRING_LIST_INIT_DUP;
 	struct strbuf line = STRBUF_INIT;
-	struct progress *progress;
+	struct progress *progress = NULL;
 
 	const char *usage[] = {
-		"test-tool progress [--total=<n>] <progress-title>",
+		"test-tool progress <stdin",
 		NULL
 	};
 	struct option options[] = {
-		OPT_INTEGER(0, "total", &total, "total number of items"),
 		OPT_END(),
 	};
 
 	argc = parse_options(argc, argv, NULL, options, usage, 0);
-	if (argc != 1)
-		die("need a title for the progress output");
-	title = argv[0];
+	if (argc)
+		usage_with_options(usage, options);
 
 	progress_testing = 1;
-	progress = start_progress(title, total);
 	while (strbuf_getline(&line, stdin) != EOF) {
 		char *end;
 
-		if (skip_prefix(line.buf, "progress ", (const char **) &end)) {
+		if (skip_prefix(line.buf, "start ", (const char **) &end)) {
+			uint64_t total = strtoull(end, &end, 10);
+			const char *title;
+			const char *str;
+
+			/*
+			 * We can't use "end + 1" as an argument to
+			 * start_progress(), it doesn't xstrdup() its
+			 * "title" argument. We need to hold onto a
+			 * valid "char *" for it until the end.
+			 */
+			if (!*end)
+				title = default_title;
+			else if (*end == ' ')
+				title = string_list_insert(&titles, end + 1)->string;
+			else
+				die("invalid input: '%s'\n", line.buf);
+
+			str = title ? title : default_title;
+			progress = start_progress(str, total);
+		} else if (skip_prefix(line.buf, "progress ", (const char **) &end)) {
 			uint64_t item_count = strtoull(end, &end, 10);
 			if (*end != '\0')
 				die("invalid input: '%s'\n", line.buf);
@@ -65,12 +87,14 @@ int cmd__progress(int argc, const char **argv)
 			display_throughput(progress, byte_count);
 		} else if (!strcmp(line.buf, "update")) {
 			progress_test_force_update();
+		} else if (!strcmp(line.buf, "stop")) {
+			stop_progress(&progress);
 		} else {
 			die("invalid input: '%s'\n", line.buf);
 		}
 	}
-	stop_progress(&progress);
 	strbuf_release(&line);
+	string_list_clear(&titles, 0);
 
 	return 0;
 }
diff --git a/t/t0500-progress-display.sh b/t/t0500-progress-display.sh
index f37cf2eb9c9..27ab4218b01 100755
--- a/t/t0500-progress-display.sh
+++ b/t/t0500-progress-display.sh
@@ -18,6 +18,7 @@ test_expect_success 'simple progress display' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 0
 	update
 	progress 1
 	update
@@ -26,8 +27,9 @@ test_expect_success 'simple progress display' '
 	progress 4
 	update
 	progress 5
+	stop
 	EOF
-	test-tool progress "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -42,11 +44,13 @@ test_expect_success 'progress display with total' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 3
 	progress 1
 	progress 2
 	progress 3
+	stop
 	EOF
-	test-tool progress --total=3 "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -63,14 +67,14 @@ Working hard.......2.........3.........4.........5.........6:
 EOF
 
 	cat >in <<-\EOF &&
+	start 100000 Working hard.......2.........3.........4.........5.........6
 	progress 100
 	progress 1000
 	progress 10000
 	progress 100000
+	stop
 	EOF
-	test-tool progress --total=100000 \
-		"Working hard.......2.........3.........4.........5.........6" \
-		<in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -89,16 +93,16 @@ Working hard.......2.........3.........4.........5.........6:
 EOF
 
 	cat >in <<-\EOF &&
+	start 100000 Working hard.......2.........3.........4.........5.........6
 	update
 	progress 1
 	update
 	progress 2
 	progress 10000
 	progress 100000
+	stop
 	EOF
-	test-tool progress --total=100000 \
-		"Working hard.......2.........3.........4.........5.........6" \
-		<in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -117,14 +121,14 @@ Working hard.......2.........3.........4.........5.........6:
 EOF
 
 	cat >in <<-\EOF &&
+	start 100000 Working hard.......2.........3.........4.........5.........6
 	progress 25000
 	progress 50000
 	progress 75000
 	progress 100000
+	stop
 	EOF
-	test-tool progress --total=100000 \
-		"Working hard.......2.........3.........4.........5.........6" \
-		<in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -141,14 +145,14 @@ Working hard.......2.........3.........4.........5.........6.........7.........:
 EOF
 
 	cat >in <<-\EOF &&
+	start 100000 Working hard.......2.........3.........4.........5.........6.........7.........
 	progress 25000
 	progress 50000
 	progress 75000
 	progress 100000
+	stop
 	EOF
-	test-tool progress --total=100000 \
-		"Working hard.......2.........3.........4.........5.........6.........7........." \
-		<in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -165,12 +169,14 @@ test_expect_success 'progress shortens - crazy caller' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 1000
 	progress 100
 	progress 200
 	progress 1
 	progress 1000
+	stop
 	EOF
-	test-tool progress --total=1000 "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -186,6 +192,7 @@ test_expect_success 'progress display with throughput' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 0
 	throughput 102400 1000
 	update
 	progress 10
@@ -198,8 +205,9 @@ test_expect_success 'progress display with throughput' '
 	throughput 409600 4000
 	update
 	progress 40
+	stop
 	EOF
-	test-tool progress "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -215,6 +223,7 @@ test_expect_success 'progress display with throughput and total' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 40
 	throughput 102400 1000
 	progress 10
 	throughput 204800 2000
@@ -223,8 +232,9 @@ test_expect_success 'progress display with throughput and total' '
 	progress 30
 	throughput 409600 4000
 	progress 40
+	stop
 	EOF
-	test-tool progress --total=40 "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -240,6 +250,7 @@ test_expect_success 'cover up after throughput shortens' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 0
 	throughput 409600 1000
 	update
 	progress 1
@@ -252,8 +263,9 @@ test_expect_success 'cover up after throughput shortens' '
 	throughput 1638400 4000
 	update
 	progress 4
+	stop
 	EOF
-	test-tool progress "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -268,6 +280,7 @@ test_expect_success 'cover up after throughput shortens a lot' '
 	EOF
 
 	cat >in <<-\EOF &&
+	start 0
 	throughput 1 1000
 	update
 	progress 1
@@ -277,8 +290,9 @@ test_expect_success 'cover up after throughput shortens a lot' '
 	throughput 3145728 3000
 	update
 	progress 3
+	stop
 	EOF
-	test-tool progress "Working hard" <in 2>stderr &&
+	test-tool progress <in 2>stderr &&
 
 	show_cr <stderr >out &&
 	test_cmp expect out
@@ -286,6 +300,7 @@ test_expect_success 'cover up after throughput shortens a lot' '
 
 test_expect_success 'progress generates traces' '
 	cat >in <<-\EOF &&
+	start 40
 	throughput 102400 1000
 	update
 	progress 10
@@ -298,10 +313,11 @@ test_expect_success 'progress generates traces' '
 	throughput 409600 4000
 	update
 	progress 40
+	stop
 	EOF
 
-	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool progress --total=40 \
-		"Working hard" <in 2>stderr &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool progress \
+		<in 2>stderr &&
 
 	# t0212/parse_events.perl intentionally omits regions and data.
 	test_region progress "Working hard" trace.event &&
-- 
2.34.1.1257.g2af47340c7b