1 files changed, 108 insertions, 0 deletions
diff --git a/lib/ccan/tally/test/run-histogram.c b/lib/ccan/tally/test/run-histogram.c
new file mode 100644
index 00000000000..a9894ecd853
--- /dev/null
+++ b/lib/ccan/tally/test/run-histogram.c
@@ -0,0 +1,108 @@
+#include <ccan/tally/tally.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+	int i;
+	struct tally *tally;
+	char *graph, *p;
+
+	plan_tests(100 + 1 + 10 + 1 + 100 + 1 + 10 + 1 + 10 * 2 + 1);
+
+	/* Uniform distribution, easy. */
+	tally = tally_new(100);
+	for (i = 0; i < 100; i++)
+		tally_add(tally, i);
+
+	/* 1:1 height. */
+	graph = p = tally_histogram(tally, 20, 100);
+	for (i = 0; i < 100; i++) {
+		char *eol = strchr(p, '\n');
+
+		/* We expect it filled all way to the end. */
+		ok1(eol - p == 20);
+		p = eol + 1;
+	}
+	ok1(!*p);
+	free(graph);
+
+	/* Reduced height. */
+	graph = p = tally_histogram(tally, 20, 10);
+	for (i = 0; i < 10; i++) {
+		char *eol = strchr(p, '\n');
+
+		/* First once can be truncated (bucket aliasing) */
+		if (eol) {
+			ok1(eol - p == 20 || (eol - p < 20 && i == 0));
+		} else
+			/* We should, at worst, half-fill graph */
+			ok1(i > 5);
+
+		if (eol)
+			p = eol + 1;
+	}
+	ok1(!*p);
+	free(graph);
+
+	/* Enlarged height (gets capped). */
+	graph = p = tally_histogram(tally, 20, 1000);
+	for (i = 0; i < 100; i++) {
+		char *eol = strchr(p, '\n');
+		/* We expect it filled all way to the end. */
+		ok1(eol - p == 20);
+		p = eol + 1;
+	}
+	ok1(!*p);
+	free(graph);
+	free(tally);
+
+	/* Distinctive increasing pattern. */
+	tally = tally_new(10);
+	for (i = 0; i < 10; i++) {
+		unsigned int j;
+		for (j = 0; j <= i; j++)
+			tally_add(tally, i);
+	}
+
+	graph = p = tally_histogram(tally, 10, 10);
+	for (i = 0; i < 10; i++) {
+		char *eol = strchr(p, '\n');
+		ok1(eol - p == 10 - i);
+		p = eol + 1;
+	}
+	ok1(!*p);
+	diag("Here's the pretty: %s", graph);
+	free(graph);
+	free(tally);
+
+	/* With negative values. */
+	tally = tally_new(10);
+	for (i = 0; i < 10; i++) {
+		tally_add(tally, i - 5);
+	}
+
+	graph = p = tally_histogram(tally, 10, 10);
+	for (i = 0; i < 10; i++) {
+		char *eol = strchr(p, '\n');
+
+		/* We expect it filled all way to the end. */
+		ok1(eol - p == 10);
+
+		/* Check min/max labels. */
+		if (i == 0)
+			ok1(strncmp(p, "4*", 2) == 0);
+		else if (i == 9)
+			ok1(strncmp(p, "-5*", 3) == 0);
+		else if (i == 4)
+			ok1(p[0] == '+'); /* 0 marker */
+		else
+			ok1(p[0] == '|');
+		p = eol + 1;
+	}
+	ok1(!*p);
+	diag("Here's the pretty: %s", graph);
+	free(graph);
+	free(tally);
+
+	return exit_status();
+}