Make error handlers treat any failures as fatal

A lot of existing tests that expect errors to be reported do not check
the returned result. This change treats failures of the error handler
in that situation as fatal.

The default error handler already behaved that way. The others did not.

FixtureExpectsAllErrorsToMatchAPattern uses
CheckErrorsAgainstExpectations and it was safe to just make that func
treat any unmatching errors as fatal as all the existing usages are at
the end of test functions.

FixtureExpectsAtLeastOneErrorMatchingPattern uses the
FailIfNoMatchingErrors function which is used in a number of places
(including CheckErrorsAgainstExpectations) that do not want to treat
a test failure as fatal. So, that was modified to return false if no
matching error was found and the error handler treated that as fatal.

Bug: 181070625
Test: m nothing
Change-Id: I6e4df53f93250348bc050d4ff098134e6314ae30

android/fixture.go

@@ -396,6 +396,9 @@ func (h simpleErrorHandler) CheckErrors(result *TestResult, errs []error) {
 // The default fixture error handler.
 //
 // Will fail the test immediately if any errors are reported.
+//
+// If the test fails this handler will call `result.FailNow()` which will exit the goroutine within
+// which the test is being run which means that the RunTest() method will not return.
 var FixtureExpectsNoErrors = FixtureCustomErrorHandler(
 	func(result *TestResult, errs []error) {
 		FailIfErrored(result.T, errs)
@@ -411,9 +414,14 @@ var FixtureExpectsNoErrors = FixtureCustomErrorHandler(
 //
 // The test will not fail if:
 // * Multiple errors are reported that do not match the pattern as long as one does match.
+//
+// If the test fails this handler will call `result.FailNow()` which will exit the goroutine within
+// which the test is being run which means that the RunTest() method will not return.
 func FixtureExpectsAtLeastOneErrorMatchingPattern(pattern string) FixtureErrorHandler {
 	return FixtureCustomErrorHandler(func(result *TestResult, errs []error) {
-		FailIfNoMatchingErrors(result.T, pattern, errs)
+		if !FailIfNoMatchingErrors(result.T, pattern, errs) {
+			result.FailNow()
+		}
 	})
 }
 
@@ -427,6 +435,9 @@ func FixtureExpectsAtLeastOneErrorMatchingPattern(pattern string) FixtureErrorHa
 //
 // The test will not fail if:
 // * One or more of the patterns does not match an error.
+//
+// If the test fails this handler will call `result.FailNow()` which will exit the goroutine within
+// which the test is being run which means that the RunTest() method will not return.
 func FixtureExpectsAllErrorsToMatchAPattern(patterns []string) FixtureErrorHandler {
 	return FixtureCustomErrorHandler(func(result *TestResult, errs []error) {
 		CheckErrorsAgainstExpectations(result.T, errs, patterns)

android/testing.go

@@ -456,12 +456,15 @@ func FailIfErrored(t *testing.T, errs []error) {
 	}
 }
 
-func FailIfNoMatchingErrors(t *testing.T, pattern string, errs []error) {
+// Fail if no errors that matched the regular expression were found.
+//
+// Returns true if a matching error was found, false otherwise.
+func FailIfNoMatchingErrors(t *testing.T, pattern string, errs []error) bool {
 	t.Helper()
 
 	matcher, err := regexp.Compile(pattern)
 	if err != nil {
-		t.Errorf("failed to compile regular expression %q because %s", pattern, err)
+		t.Fatalf("failed to compile regular expression %q because %s", pattern, err)
 	}
 
 	found := false
@@ -477,6 +480,8 @@ func FailIfNoMatchingErrors(t *testing.T, pattern string, errs []error) {
 			t.Errorf("errs[%d] = %q", i, err)
 		}
 	}
+
+	return found
 }
 
 func CheckErrorsAgainstExpectations(t *testing.T, errs []error, expectedErrorPatterns []string) {
@@ -497,9 +502,9 @@ func CheckErrorsAgainstExpectations(t *testing.T, errs []error, expectedErrorPat
 			for i, err := range errs {
 				t.Errorf("errs[%d] = %s", i, err)
 			}
+			t.FailNow()
 		}
 	}
-
 }
 
 func SetKatiEnabledForTests(config Config) {