From 6bba99fce1a25725182f22701ac3d74b965d7454 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Tue, 17 Mar 2020 14:33:30 -0700
Subject: [PATCH] add testStrEq()

---
 src/pvxs/unittest.h |  9 ++++++++
 src/unittest.cpp    | 56 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/src/pvxs/unittest.h b/src/pvxs/unittest.h
index daf331f..c6a3b82 100644
--- a/src/pvxs/unittest.h
+++ b/src/pvxs/unittest.h
@@ -122,6 +122,9 @@ testCase testNotEq(const char *sLHS, const LHS& lhs, const char *sRHS, const RHS
     return ret;
 }
 
+PVXS_API
+testCase _testStrEq(const char *sLHS, const std::string& lhs, const char *sRHS, const std::string& rhs);
+
 } // namespace detail
 
 /** Assert that an exception is thrown.
@@ -175,6 +178,12 @@ testCase testThrows(FN fn)
 //! Roughly equivalent to @code testOk((LHS)!=(RHS), "..."); @endcode
 #define testNotEq(LHS, RHS) ::pvxs::detail::testNotEq(#LHS, LHS, #RHS, RHS)
 
+//! Macro which asserts equality between LHS and RHS.
+//! Evaluates to a pvxs::testCase
+//! Functionally equivalent to testEq() with two std::string instances.
+//! Prints diff-like output which is friendlier to multi-line strings.
+#define testStrEq(LHS, RHS) ::pvxs::detail::_testStrEq(#LHS, LHS, #RHS, RHS)
+
 //! Macro which prints diagnostic (non-test) lines.
 //! Evaluates to a pvxs::testCase
 //! Roughly equivalent to @code testDiag("..."); @endcode
diff --git a/src/unittest.cpp b/src/unittest.cpp
index d7a3465..909fe89 100644
--- a/src/unittest.cpp
+++ b/src/unittest.cpp
@@ -7,6 +7,7 @@
 #include <epicsUnitTest.h>
 
 #include "pvxs/unittest.h"
+#include "utilpvt.h"
 
 namespace pvxs {
 
@@ -63,4 +64,59 @@ testCase::~testCase()
     }
 }
 
+namespace detail {
+
+size_t findNextLine(const std::string& s, size_t pos=0u)
+{
+    size_t next = s.find_first_of('\n', pos);
+    if(next!=std::string::npos)
+        next++;
+    return next;
+}
+
+testCase _testStrEq(const char *sLHS, const std::string& lhs, const char *sRHS, const std::string& rhs)
+{
+    testCase ret(lhs==rhs);
+    ret<<sLHS<<" == "<<sRHS<<"\n";
+
+    size_t posL=0u, posR=0u;
+
+    while(posL<lhs.size() && posR<rhs.size()) {
+        size_t eolL = findNextLine(lhs, posL);
+        size_t eolR = findNextLine(rhs, posR);
+
+        auto L = lhs.substr(posL, eolL-posL);
+        auto R = rhs.substr(posR, eolR-posR);
+
+        if(L==R) {
+            ret<<"  \""<<escape(L)<<"\"\n";
+        } else {
+            ret<<"+ \""<<escape(R)<<"\"\n";
+            ret<<"- \""<<escape(L)<<"\"\n";
+        }
+
+        posL = eolL;
+        posR = eolR;
+    }
+
+    while(posR<rhs.size()) {
+        size_t eol = findNextLine(rhs, posR);
+        auto line = rhs.substr(posR, eol-posR);
+        ret<<"+ \""<<escape(line)<<"\"\n";
+
+        posR = eol;
+    }
+
+    while(posL<lhs.size()) {
+        size_t eol = findNextLine(lhs, posL);
+        auto line = lhs.substr(posL, eol-posL);
+        ret<<"- \""<<escape(line)<<"\"\n";
+
+        posL = eol;
+    }
+
+    return ret;
+}
+
+} // namespace detail
 } // namespace pvxs