From 001edb9a7a78bc6430251cf0d6371e48db248577 Mon Sep 17 00:00:00 2001
From: fallenoak <git@fallenoak.me>
Date: Mon, 16 Nov 2020 17:44:08 -0600
Subject: [PATCH] feat(string): add SStrStr

---
 storm/String.cpp | 21 +++++++++++++++++++++
 storm/String.hpp |  2 ++
 test/String.cpp  | 23 +++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/storm/String.cpp b/storm/String.cpp
index f99c39e..459ac52 100644
--- a/storm/String.cpp
+++ b/storm/String.cpp
@@ -219,3 +219,24 @@ size_t SStrLen(const char* string) {
         ;
     return c - string;
 }
+
+const char* SStrStr(const char* string, const char* search) {
+    STORM_ASSERT(string);
+    STORM_ASSERT(search);
+
+    const char* i;
+    for (i = search; *i; ++i);
+    size_t length = i - search;
+
+    const char* substring = string;
+
+    if (!*substring) {
+        return nullptr;
+    }
+
+    while (*substring && SStrCmp(substring, search, length)) {
+        substring++;
+    }
+
+    return substring;
+}
diff --git a/storm/String.hpp b/storm/String.hpp
index aa9b1cc..fa4fb25 100644
--- a/storm/String.hpp
+++ b/storm/String.hpp
@@ -19,4 +19,6 @@ uint32_t SStrHashHT(const char* string);
 
 size_t SStrLen(const char* string);
 
+const char* SStrStr(const char* string, const char* search);
+
 #endif
diff --git a/test/String.cpp b/test/String.cpp
index 70ce93c..dd823b1 100644
--- a/test/String.cpp
+++ b/test/String.cpp
@@ -75,3 +75,26 @@ TEST_CASE("SStrLen", "[string]") {
         REQUIRE(length == 3);
     }
 }
+
+TEST_CASE("SStrStr", "[string]") {
+    SECTION("finds substring when it exists at end of string") {
+        auto string = "foobar";
+        auto search = "bar";
+        auto substring = SStrStr(string, search);
+        REQUIRE(!SStrCmp(search, substring, SStrLen(search)));
+    }
+
+    SECTION("finds substring when it exists at start of string") {
+        auto string = "foobar";
+        auto search = "foo";
+        auto substring = SStrStr(string, search);
+        REQUIRE(!SStrCmp(search, substring, SStrLen(search)));
+    }
+
+    SECTION("returns nullptr when given empty string") {
+        auto string = "";
+        auto search = "bar";
+        auto substring = SStrStr(string, search);
+        REQUIRE(substring == nullptr);
+    }
+}