test: Fail CDP commands on unhandled exceptions

Install a Chrome Devtools Protocol handler for unhandled exceptions, and
fail the next CDP command with it.  This got lost with the move from
PhantomJS to Chrome.

Some of our tests rely on failed ph_* function invocations, so we must
not log failures of ph_wait_cond(); these  are also technically
unhandled exceptions. So turn this into a proper `PhWaitCondTimeout`
error class, so that it can be identified reliably.

Handle cases where undefined value is passed to fail/success in
cdp-driver.js.

Adjust the naughty override for the XTerm.js crash (#9641) as this now
shows the actual underlying crash instead of just the followup element
wait timeout.

Closes #9639

bots/naughty/debian-stable/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/debian-testing/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/fedora-27/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/fedora-28/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/rhel-7/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/rhel-x/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/ubuntu-1604/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

bots/naughty/ubuntu-stable/9641-xtermjs-dimensions-crash

@@ -1,5 +1,4 @@
 Traceback (most recent call last):
   File "test/verify/check-machines", line *, in testSerialConsole
-    b.wait_not_present("div.terminal canvas.xterm-text-layer")
 *
-Error: timeout
+RuntimeError: TypeError: Cannot read property 'dimensions' of undefined

test/common/cdp-driver.js

@@ -47,11 +47,15 @@ function fatal() {
 }
 
 function fail(err) {
+    if (typeof err === 'undefined')
+        err = null;
     process.stdout.write(JSON.stringify({"error": err}) + '\n');
 }
 
 function success(result) {
-    process.stdout.write(JSON.stringify({"result": result === undefined ? null : result}) + '\n');
+    if (typeof result === 'undefined')
+        result = null;
+    process.stdout.write(JSON.stringify({"result": result}) + '\n');
 }
 
 /**
@@ -61,6 +65,7 @@ function success(result) {
 var messages = [];
 var logPromiseResolver;
 var nReportedLogMessages = 0;
+var unhandledExceptions = [];
 
 function setupLogging(client) {
     client.Runtime.enable();
@@ -72,6 +77,16 @@ function setupLogging(client) {
         resolveLogPromise();
     });
 
+    client.Runtime.exceptionThrown(info => {
+        let details = info.exceptionDetails;
+        // don't log test timeouts, they already get handled
+        if (details.exception && details.exception.className === "PhWaitCondTimeout")
+            return;
+
+        unhandledExceptions.push(details)
+        process.stderr.write(details.description || JSON.stringify(details) + "\n");
+    });
+
     client.Log.enable();
     client.Log.entryAdded(entry => {
         let msg = entry["entry"];
@@ -288,7 +303,19 @@ CDP.New(options)
                                 pageLoadPromise = new Promise((resolve, reject) => { pageLoadResolve = resolve; pageLoadReject = reject; });
 
                             // run the command
-                            eval(command).then(success, fail);
+                            eval(command).then(reply => {
+                                if (unhandledExceptions.length === 0) {
+                                    success(reply);
+                                } else {
+                                    let details = unhandledExceptions[0];
+                                    let message = details.exception.message ||
+                                                  details.exception.description ||
+                                                  details.exception.value ||
+                                                  JSON.stringify(details.exception);
+                                    fail(message.split("\n")[0]);
+                                    unhandledExceptions.length = 0;
+                                }
+                            }, fail);
 
                             input_buf = input_buf.slice(i+1);
                         }

test/common/test-functions.js

@@ -184,6 +184,12 @@ function ph_focus(sel)
     ph_find(sel).focus();
 }
 
+class PhWaitCondTimeout extends Error {
+    constructor() {
+        super("condition did not become true");
+    }
+}
+
 function ph_wait_cond(cond, timeout) {
     return new Promise((resolve, reject) => {
         // poll every 100 ms for now;  FIXME: poll less often and re-check on mutations using
@@ -192,7 +198,7 @@ function ph_wait_cond(cond, timeout) {
         let tm = window.setTimeout( () => {
                 if (stepTimer)
                     window.clearTimeout(stepTimer);
-                reject("condition did not become true");
+                reject(new PhWaitCondTimeout());
             }, timeout);
         function step() {
             try {