go/analysis/analysistest: Ignore error when...

...changed file cannot be formatted

There are instances when the diagnostics are reported correctly by the
analyzer, but the suggested fixes are wrong, and result in code that
cannot be formatted by `format.Source` (maybe due to syntax errors in
the edited code).  Right now, in those cases, the test runner ignores
the failed tests and moves on to the next test, giving an impression
that the tests have passed. This commit fixes that.

Signed-off-by: Sourya Vatsyayan <[email protected]>

Author: sourya

go/analysis/analysistest/analysistest.go

@@ -65,6 +65,7 @@ var TestData = func() string {
 // Testing is an abstraction of a *testing.T.
 type Testing interface {
 	Errorf(format string, args ...interface{})
+	Skipf(format string, args ...interface{})
 }
 
 // RunWithSuggestedFixes behaves like Run, but additionally verifies suggested fixes.
@@ -183,7 +184,7 @@ func RunWithSuggestedFixes(t Testing, dir string, a *analysis.Analyzer, patterns
 						want := string(bytes.TrimRight(vf.Data, "\n")) + "\n"
 						formatted, err := format.Source([]byte(out))
 						if err != nil {
-							continue
+							t.Skipf("Could not format edited file %s. Error: %s. Continuing nevertheless\n", file.Name(), err)
 						}
 						if want != string(formatted) {
 							d := myers.ComputeEdits("", want, string(formatted))
@@ -209,6 +210,7 @@ func RunWithSuggestedFixes(t Testing, dir string, a *analysis.Analyzer, patterns
 
 			formatted, err := format.Source([]byte(out))
 			if err != nil {
+				t.Errorf("Could not format edited file %s. Error: %s", file.Name(), err)
 				continue
 			}
 			if want != string(formatted) {

go/analysis/analysistest/analysistest_test.go

@@ -141,3 +141,7 @@ type errorfunc func(string)
 func (f errorfunc) Errorf(format string, args ...interface{}) {
 	f(fmt.Sprintf(format, args...))
 }
+
+func (f errorfunc) Skipf(format string, args ...interface{}) {
+	f(fmt.Sprintf(format, args...))
+}