From 6f9867cba65f806eeb652606bd4010ed04e0e07c Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Sun, 20 May 2018 01:35:42 -0400
Subject: [PATCH] fix validate pagination params

---
 rpc/core/pipe.go      |  8 ++++--
 rpc/core/pipe_test.go | 67 +++++++++++++++++++++++++++++++++++++++++++
 rpc/core/tx.go        |  2 +-
 3 files changed, 74 insertions(+), 3 deletions(-)
 create mode 100644 rpc/core/pipe_test.go

diff --git a/rpc/core/pipe.go b/rpc/core/pipe.go
index f97d1817a..e4bb5a294 100644
--- a/rpc/core/pipe.go
+++ b/rpc/core/pipe.go
@@ -124,10 +124,14 @@ func SetEventBus(b *types.EventBus) {
 	eventBus = b
 }
 
-func validatePage(page int) int {
+func validatePage(page, perPage, totalCount int) int {
+	pages := ((totalCount - 1) / perPage) + 1
 	if page < 1 {
-		return 1
+		page = 1
+	} else if page > pages {
+		page = pages
 	}
+
 	return page
 }
 
diff --git a/rpc/core/pipe_test.go b/rpc/core/pipe_test.go
new file mode 100644
index 000000000..a33e17cf4
--- /dev/null
+++ b/rpc/core/pipe_test.go
@@ -0,0 +1,67 @@
+package core
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPaginationPage(t *testing.T) {
+
+	cases := []struct {
+		totalCount int
+		perPage    int
+		page       int
+		newPage    int
+	}{
+		{0, 10, 0, 1},
+		{0, 10, 1, 1},
+		{0, 10, 2, 1},
+
+		{5, 10, -1, 1},
+		{5, 10, 0, 1},
+		{5, 10, 1, 1},
+		{5, 10, 2, 1},
+		{5, 10, 2, 1},
+
+		{5, 5, 1, 1},
+		{5, 5, 2, 1},
+		{5, 5, 3, 1},
+
+		{5, 3, 2, 2},
+		{5, 3, 3, 2},
+
+		{5, 2, 2, 2},
+		{5, 2, 3, 3},
+		{5, 2, 4, 3},
+	}
+
+	for _, c := range cases {
+		p := validatePage(c.page, c.perPage, c.totalCount)
+		assert.Equal(t, c.newPage, p, fmt.Sprintf("%v", c))
+	}
+
+}
+
+func TestPaginationPerPage(t *testing.T) {
+
+	cases := []struct {
+		totalCount int
+		perPage    int
+		newPerPage int
+	}{
+		{5, 0, defaultPerPage},
+		{5, 1, 1},
+		{5, 2, 2},
+		{5, defaultPerPage, defaultPerPage},
+		{5, maxPerPage - 1, maxPerPage - 1},
+		{5, maxPerPage, maxPerPage},
+		{5, maxPerPage + 1, defaultPerPage},
+	}
+
+	for _, c := range cases {
+		p := validatePerPage(c.perPage)
+		assert.Equal(t, c.newPerPage, p, fmt.Sprintf("%v", c))
+	}
+}
diff --git a/rpc/core/tx.go b/rpc/core/tx.go
index ba68331e2..5fc01a86d 100644
--- a/rpc/core/tx.go
+++ b/rpc/core/tx.go
@@ -188,7 +188,7 @@ func TxSearch(query string, prove bool, page, perPage int) (*ctypes.ResultTxSear
 	}
 
 	totalCount := len(results)
-	page = validatePage(page)
+	page = validatePage(page, perPage, totalCount)
 	perPage = validatePerPage(perPage)
 	skipCount := (page - 1) * perPage