From c76ef3e52f3e4fb387592f5a80706039b9656712 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@gmail.com>
Date: Thu, 7 Jan 2021 09:36:44 -0800
Subject: [PATCH] unittest: add testThrowsMatch() and testStrMatch()

---
 documentation/util.rst |  8 ++++++++
 src/pvxs/unittest.h    | 46 ++++++++++++++++++++++++++++++++++++++++++
 src/unittest.cpp       | 25 +++++++++++++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/documentation/util.rst b/documentation/util.rst
index 88b1867..53a4bc7 100644
--- a/documentation/util.rst
+++ b/documentation/util.rst
@@ -110,6 +110,12 @@ Extensions to epicsUnitTest.h ::
 
 .. doxygendefine:: testNotEq
 
+.. doxygendefine:: testStrEq
+
+.. doxygendefine:: testStrMatch
+
+.. doxygendefine:: testArrEq
+
 .. doxygendefine:: testShow
 
 The testEq() macro and friends expand to a function which returns a `pvxs::testCase` instance
@@ -122,6 +128,8 @@ which may be used as a `std::ostream` to append text describing a test. eg. ::
 
 .. doxygenfunction:: pvxs::testThrows
 
+.. doxygenfunction:: pvxs::testThrowsMatch
+
 .. doxygenclass:: pvxs::testCase
     :members:
 
diff --git a/src/pvxs/unittest.h b/src/pvxs/unittest.h
index 265cf01..b4548ce 100644
--- a/src/pvxs/unittest.h
+++ b/src/pvxs/unittest.h
@@ -78,6 +78,10 @@ public:
         return *this;
     }
 
+    //! Override current pass/fail result if input matches a regular expression
+    //! @since UNRELEASED
+    testCase& setPassMatch(const std::string& expr, const std::string& inp);
+
     //! Append to message
     template<typename T>
     inline testCase& operator<<(const T& v) {
@@ -145,6 +149,9 @@ testCase testNotEq(const char *sLHS, const LHS& lhs, const char *sRHS, const RHS
 PVXS_API
 testCase _testStrEq(const char *sLHS, const std::string& lhs, const char *sRHS, const std::string& rhs);
 
+PVXS_API
+testCase _testStrMatch(const char *spat, const std::string& pat, const char *sstr, const std::string& str);
+
 template<typename LHS, typename RHS>
 testCase testArrEq(const char *sLHS, const LHS& lhs, const char *sRHS, const RHS& rhs)
 {
@@ -198,6 +205,40 @@ testCase testThrows(FN fn)
     return ret;
 }
 
+/** Assert that an exception is throw with a certain message.
+ *
+ * @tparam Exception The exception type which should be thrown
+ * @param expr A regular expression
+ * @param fn A callable
+ *
+ * @returns A testCase which passes if an Exception instance was caught
+ *          and std::exception::what() matched the provided regular expression.
+ *
+ * @code
+ * testThrowsMatch<std::runtime_error>("happened", []() {
+ *      testShow()<<"Now you see me";
+ *      throw std::runtime_error("I happened");
+ *      testShow()<<"Now you don't";
+ * })<<"some message";
+ * @endcode
+ *
+ * @since UNRELEASED
+ */
+template<class Exception, typename FN>
+testCase testThrowsMatch(const std::string& expr, FN fn)
+{
+    testCase ret(false);
+    try {
+        fn();
+        ret<<"Unexpected success - ";
+    }catch(Exception& e){
+        ret.setPassMatch(expr, e.what())<<"Expected matching (\""<<expr<<"\") exception \""<<e.what()<<"\" - ";
+    }catch(std::exception& e){
+        ret<<"Unexpected exception "<<typeid(e).name()<<" \""<<e.what()<<"\" - ";
+    }
+    return ret;
+}
+
 } // namespace pvxs
 
 //! Macro which assert that an expression evaluate to 'true'.
@@ -224,6 +265,11 @@ testCase testThrows(FN fn)
 //! Prints diff-like output which is friendlier to multi-line strings.
 #define testStrEq(LHS, RHS) ::pvxs::detail::_testStrEq(#LHS, LHS, #RHS, RHS)
 
+//! Macro which asserts that STR matches the regular expression EXPR
+//! Evaluates to a pvxs::testCase
+//! @since UNRELEASED
+#define testStrMatch(EXPR, STR) ::pvxs::detail::_testStrMatch(#EXPR, EXPR, #STR, STR)
+
 //! Macro which asserts equality between LHS and RHS.
 //! Evaluates to a pvxs::testCase
 //! Functionally equivalent to testEq() for objects with .size() and operator[].
diff --git a/src/unittest.cpp b/src/unittest.cpp
index 72c6ec7..b1d2fef 100644
--- a/src/unittest.cpp
+++ b/src/unittest.cpp
@@ -4,6 +4,8 @@
  * in file LICENSE that is included with this distribution.
  */
 
+#include <regex>
+
 #include <epicsUnitTest.h>
 
 #include "pvxs/unittest.h"
@@ -92,6 +94,20 @@ testCase::~testCase()
     }
 }
 
+testCase& testCase::setPassMatch(const std::string& expr, const std::string& inp)
+{
+    std::regex ex;
+    try {
+        ex.assign(expr);
+        setPass(std::regex_match(inp, ex));
+
+    }catch(std::regex_error& e) {
+        setPass(false);
+        (*this)<<" expression error: "<<e.what()<<" :";
+    }
+    return *this;
+}
+
 namespace detail {
 
 size_t findNextLine(const std::string& s, size_t pos=0u)
@@ -146,5 +162,14 @@ testCase _testStrEq(const char *sLHS, const std::string& lhs, const char *sRHS,
     return ret;
 }
 
+testCase _testStrMatch(const char *spat, const std::string& pat, const char *sstr, const std::string& str)
+{
+    std::regex expr;
+    testCase ret;
+    ret.setPassMatch(pat, str);
+    ret<<spat<<" (\""<<pat<<"\") match "<<str<<" (\""<<escape(str)<<"\")";
+    return ret;
+}
+
 } // namespace detail
 } // namespace pvxs