[ENC-2013] Add support for caputring test logs (#27)

overlay/src/testing/encore_app.go

@@ -7,7 +7,7 @@ import _ "unsafe"
 
 // encoreStartTest is called when a test starts running. This allows Encore's testing framework to
 // isolate behavior between different tests on global state. It is linked to the Encore runtime via go:linkname.
-func encoreStartTest(t *T)
+func encoreStartTest(t *T, fn func(t *T))
 
 // encoreEndTest is called when a test ends. This allows Encore's testing framework to clear down any state from the test
 // and to perform any assertions on that state that it needs to. It is linked to the Encore runtime via go:linkname.
@@ -20,3 +20,7 @@ func encorePauseTest(t *T)
 // encoreResumeTest is called when a test is resumed after being paused. This allows Encore's testing framework to clear down any state from the test
 // and to perform any assertions on that state that it needs to. It is linked to the Encore runtime via go:linkname.
 func encoreResumeTest(t *T)
+
+// encoreTestLog is called when a test logs a line. This allows Encore's testing framework to capture the log output
+// and emit that log output to the test trace.
+func encoreTestLog(line string, frameSkip int)

overlay/src/testing/encore_noapp.go

@@ -7,7 +7,7 @@ package testing
 // isolate behavior between different tests on global state.
 //
 // This implementation is simply a no-op as it's used when the tests are not being run against an Encore application
-func encoreStartTest(t *T) {}
+func encoreStartTest(t *T, fn func(t *T)) {}
 
 // encoreEndTest is called when a test ends. This allows Encore's testing framework to clear down any state from the test
 // and to perform any assertions on that state that it needs to. It is linked to the Encore runtime via go:linkname.
@@ -22,3 +22,7 @@ func encorePauseTest(t *T) {}
 // encoreResumeTest is called when a test is resumed after being paused. This allows Encore's testing framework to clear down any state from the test
 // and to perform any assertions on that state that it needs to. It is linked to the Encore runtime via go:linkname.
 func encoreResumeTest(t *T) {}
+
+// encoreTestLog is called when a test logs a line. This allows Encore's testing framework to capture the log output
+// and emit that log output to the test trace.
+func encoreTestLog(line string, frameSkip int) {}

patches/testing_patch.diff

@@ -6,10 +6,23 @@ test runs against global state. This patch introduces a per test level callback
 test and not have state between tests interfere with each other.
 
 diff --git a/src/testing/testing.go b/src/testing/testing.go
-index fc34cbf28b..37f54b482b 100644
+index fcf7048f23..ec628da6ed 100644
 --- a/src/testing/testing.go
 +++ b/src/testing/testing.go
-@@ -1380,10 +1380,14 @@ func (t *T) Parallel() {
+@@ -765,6 +765,12 @@ func (c *common) frameSkip(skip int) runtime.Frame {
+ // and inserts the final newline if needed and indentation spaces for formatting.
+ // This function must be called with c.mu held.
+ func (c *common) decorate(s string, skip int) string {
++	// allow encore to capture the log as well;
++	// we do it here so that all the branches which result in a log message
++	// during tests get captured, however we do it _before_ the liens get modified
++	// and indented.
++	encoreTestLog(s, skip+1)
++
+ 	frame := c.frameSkip(skip)
+ 	file := frame.File
+ 	line := frame.Line
+@@ -1399,10 +1405,14 @@ func (t *T) Parallel() {
  	}
  	running.Delete(t.name)
 
@@ -24,11 +37,11 @@ index fc34cbf28b..37f54b482b 100644
  	if t.chatty != nil {
  		t.chatty.Updatef(t.name, "=== CONT  %s\n", t.name)
  	}
-@@ -1432,12 +1436,14 @@ var errNilPanicOrGoexit = errors.New("test executed panic(nil) or runtime.Goexit
+@@ -1451,12 +1461,14 @@ var errNilPanicOrGoexit = errors.New("test executed panic(nil) or runtime.Goexit
 
  func tRunner(t *T, fn func(t *T)) {
  	t.runner = callerName(0)
-+	encoreStartTest(t)
++	encoreStartTest(t, fn)
 
  	// When this goroutine is done, either because fn(t)
  	// returned normally or because a test failure triggered