Simplify reported value

When the value of an uncaught exception is a function, AVA previously
displayed the source of that function in the error report. During the
review process for an unrelated change, this condition was found to be
too rare to justify the maintenance overhead. Do not attempt to display
the source of function values in these cases.

Author: jugglinmike

lib/serialize-error.js

@@ -92,8 +92,7 @@ module.exports = error => {
 	if (typeof error.stack === 'string') {
 		retval.summary = error.stack.split('\n')[0];
 	} else {
-		retval.summary = typeof error === 'function' ?
-			error.toString() : JSON.stringify(error);
+		retval.summary = JSON.stringify(error);
 	}
 
 	return retval;

test/cli.js

@@ -91,16 +91,6 @@ test('timeout', t => {
 	});
 });
 
-test('throwing a named function will report the to the console', t => {
-	execCli('fixture/throw-named-function.js', (err, stdout, stderr) => {
-		t.ok(err);
-		t.match(stderr, /function fooFn\(\) \{\}/);
-		// TODO(jamestalmage)
-		// t.ok(/1 uncaught exception[^s]/.test(stdout));
-		t.end();
-	});
-});
-
 test('include anonymous functions in error reports', t => {
 	execCli('fixture/error-in-anonymous-function.js', (err, stdout, stderr) => {
 		t.ok(err);
@@ -210,16 +200,6 @@ test('babel require hook only does not apply to source files', t => {
 	});
 });
 
-test('throwing a anonymous function will report the function to the console', t => {
-	execCli('fixture/throw-anonymous-function.js', (err, stdout, stderr) => {
-		t.ok(err);
-		t.match(stderr, /\(\) => \{\}/);
-		// TODO(jamestalmage)
-		// t.ok(/1 uncaught exception[^s]/.test(stdout));
-		t.end();
-	});
-});
-
 test('pkg-conf: defaults', t => {
 	execCli([], {dirname: 'fixture/pkg-conf/defaults'}, err => {
 		t.ifError(err);