lib/fold: Add text fold utility

We want to fold help text into the ncurses UI, so add a little module to
split text into lines.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 157 insertions, 0 deletions

diff --git a/test/lib/test-fold.c b/test/lib/test-fold.c
new file mode 100644
index 0000000..1f58fdf
--- /dev/null
+++ b/test/lib/test-fold.c
@@ -0,0 +1,157 @@
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <fold/fold.h>
+#include <list/list.h>
+#include <talloc/talloc.h>
+
+struct line {
+	const char		*buf;
+	unsigned int		len;
+	struct list_item	list;
+};
+
+struct ctx {
+	struct list		lines;
+};
+
+struct test {
+	const char	*in;
+	unsigned int	linelen;
+	const char	*out[];
+};
+
+/* split on newline boundaries, no actual folding */
+struct test test_split = {
+	.in	= "Lorem ipsum dolor\nsit amet,\nconsectetuer\n",
+	.linelen = 20,
+	.out = {
+		"Lorem ipsum dolor",
+		"sit amet,",
+		"consectetuer",
+		"",
+		NULL,
+	},
+};
+
+/* fold a long line */
+struct test test_fold_line = {
+	.in = "Lorem ipsum dolor sit amet, consectetuer adipiscing "
+		"elit, sed diam nonummy nibh euismod tincidunt ut "
+		"laoreet dolore magna aliquam erat volutpat.",
+	.linelen = 20,
+	.out = {
+		"Lorem ipsum dolor",
+		"sit amet,",
+		"consectetuer",
+		"adipiscing elit,",
+		"sed diam nonummy",
+		"nibh euismod",
+		"tincidunt ut",
+		"laoreet dolore",
+		"magna aliquam erat",
+		"volutpat.",
+		NULL
+	},
+};
+
+/* break a word */
+struct test test_break = {
+	.in = "Lorem ipsum dolor sit amet, consectetuer",
+	.linelen = 10,
+	.out = {
+		"Lorem",
+		"ipsum",
+		"dolor sit",
+		"amet,",
+		"consectetu",
+		"er",
+		NULL
+	},
+};
+
+static struct test *tests[] = {
+	&test_split, &test_fold_line, &test_break,
+};
+
+static void __attribute__((noreturn)) fail(struct ctx *ctx,
+		struct test *test, const char *msg)
+{
+	struct line *line;
+	int i;
+
+	fprintf(stderr, "%s\n", msg);
+	fprintf(stderr, "input:\n%s\n", test->in);
+
+	fprintf(stderr, "expected:\n");
+	for (i = 0; test->out[i]; i++)
+		fprintf(stderr, "  '%s'\n", test->out[i]);
+
+	fprintf(stderr, "actual:\n");
+	list_for_each_entry(&ctx->lines, line, list) {
+		char *buf = talloc_strndup(ctx, line->buf, line->len);
+		fprintf(stderr, "  '%s'\n", buf);
+		talloc_free(buf);
+	}
+
+	exit(EXIT_FAILURE);
+}
+
+static int fold_line_cb(void *arg, const char *start, int len)
+{
+	struct ctx *ctx = arg;
+	struct line *line;
+
+	line = talloc(ctx, struct line);
+	line->buf = start;
+	line->len = len;
+	list_add_tail(&ctx->lines, &line->list);
+
+	return 0;
+}
+
+static void run_test(struct test *test)
+{
+	struct line *line;
+	struct ctx *ctx;
+	int i;
+
+	ctx = talloc(NULL, struct ctx);
+	list_init(&ctx->lines);
+	fold_text(test->in, test->linelen, fold_line_cb, ctx);
+
+	i = 0;
+	list_for_each_entry(&ctx->lines, line, list) {
+		if (!test->out[i])
+			fail(ctx, test,
+				"fold_text returned more lines than expected");
+
+		if (line->len > test->linelen)
+			fail(ctx, test, "line too long");
+
+		if (line->len != strlen(test->out[i]))
+			fail(ctx, test, "line lengths differ");
+
+		if (strncmp(line->buf, test->out[i], line->len))
+			fail(ctx, test, "line data differs");
+
+		i++;
+	}
+
+	if (test->out[i])
+		fail(ctx, test, "fold_text returned fewer lines than expected");
+
+	talloc_free(ctx);
+}
+
+int main(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++)
+		run_test(tests[i]);
+
+	return EXIT_SUCCESS;
+}