When running DM, write test failures to json.

tests/Test.h

Index: tests/Test.h
diff --git a/tests/Test.h b/tests/Test.h
index 6c85b32bce6d95204b1ac8e66d57676f4941281c..c505a043beb834c81221f14b13bf7408070bcf2c 100644
--- a/tests/Test.h
+++ b/tests/Test.h
@@ -20,6 +20,32 @@ namespace skiatest {
 
     class Test;
 
+    struct Failure {
+        SkString fileName;

[mtklein, 2014/11/06 15:24:05]

Given that you know filename and condition are going to be compile-time constant
const char*, why not hold onto them as const char*?  Fewer refs, copies,
c_strs(), etc.

[scroggo, 2014/11/06 16:52:33]

To be fair, someone *could* skip the macro and create their own... In practice,
though, you're right, and we should discourage skipping the macro. Changed and
added comments.

+        int lineNo;
+        SkString condition;
+        SkString message;
+
+        // Helper to combine the failure message into one string.
+        static void GetFailureString(SkString* result, const Failure& failure) {

[mtklein, 2014/11/06 15:24:05]

Seems like this is simpler as SkString getFailureString() const ?

[scroggo, 2014/11/06 16:52:33]

Definitely simpler.

FWIW, I almost made it an outside function, since it doesn't deal with any
private data, but I made it a part of Failure for namespacing. Since it's a part
of Failure, I may as well make it a member function.

I'd like to keep passing result in as a parameter to avoid a copy, though.

+            if (!result) {
+                return;
+            }
+            result->printf("%s:%d\t", failure.fileName.c_str(), failure.lineNo);
+            if (!failure.message.isEmpty()) {
+                if (!failure.condition.isEmpty()) {
+                    result->appendf("%s: %s", failure.message.c_str(), failure.condition.c_str());
+                } else {
+                    result->append(failure.message);
+                }
+            } else if (!failure.condition.isEmpty()) {
+                // Condition, but no message.
+                result->append(failure.condition);
+            }
+        }
+    };
+
+
     class Reporter : public SkRefCnt {
     public:
         SK_DECLARE_INST_COUNT(Reporter)
@@ -28,7 +54,7 @@ namespace skiatest {
         int countTests() const { return fTestCount; }
 
         void startTest(Test*);
-        void reportFailed(const SkString& desc);
+        void reportFailed(const Failure&);
         void endTest(Test*);
 
         virtual bool allowExtendedTest() const { return false; }
@@ -37,7 +63,7 @@ namespace skiatest {
 
     protected:
         virtual void onStart(Test*) {}
-        virtual void onReportFailed(const SkString& desc) {}
+        virtual void onReportFailed(const Failure&) {}
         virtual void onEnd(Test*) {}
 
     private:
@@ -110,31 +136,34 @@ namespace skiatest {
     }
 */
 
-#define REPORTER_ASSERT(r, cond)                                 \
-    do {                                                         \
-        if (!(cond)) {                                           \
-            SkString desc;                                       \
-            desc.printf("%s:%d\t%s", __FILE__, __LINE__, #cond); \
-            r->reportFailed(desc);                               \
-        }                                                        \
+#define REPORTER_ASSERT(r, cond)                                        \
+    do {                                                                \
+        if (!(cond)) {                                                  \
+            skiatest::Failure failure = { SkString(__FILE__), __LINE__, \
+                                          SkString(#cond),              \
+                                          SkString() };                 \
+            r->reportFailed(failure);                                   \
+        }                                                               \
     } while(0)
 
-#define REPORTER_ASSERT_MESSAGE(r, cond, message)            \
-    do {                                                     \
-        if (!(cond)) {                                       \
-            SkString desc;                                   \
-            desc.printf("%s:%d\t%s: %s", __FILE__, __LINE__, \
-                        message, #cond);                     \
-            r->reportFailed(desc);                           \
-        }                                                    \
+#define REPORTER_ASSERT_MESSAGE(r, cond, message)                       \
+    do {                                                                \
+        if (!(cond)) {                                                  \
+            skiatest::Failure failure = { SkString(__FILE__), __LINE__, \
+                                          SkString(#cond),              \
+                                          SkString(message) };          \
+            r->reportFailed(failure);                                   \
+        }                                                               \
     } while(0)
 
-#define ERRORF(reporter, ...)                       \
-    do {                                            \
-        SkString desc;                              \
-        desc.printf("%s:%d\t", __FILE__, __LINE__); \
-        desc.appendf(__VA_ARGS__) ;                 \
-        (reporter)->reportFailed(desc);             \
+#define ERRORF(r, ...)                                                  \
+    do {                                                                \
+        SkString desc;                                                  \
+        desc.appendf(__VA_ARGS__) ;                                     \
+        skiatest::Failure failure = { SkString(__FILE__), __LINE__,     \
+                                      SkString(),                       \

[mtklein, 2014/11/06 15:24:05]

Might want something like "<ERRORF>" or "unconditional" here?

[scroggo, 2014/11/06 16:52:32]

I'm not sure that adds any more information. The other macros test a condition,
but with ERRORF the condition just happened outside the macro. The caller should
be describing the condition that reached the ERRORF line in the message.

+                                      SkString(desc) };                 \
+        r->reportFailed(failure);                                       \
     } while(0)
 
 #define DEF_TEST(name, reporter)                                        \