feat: drop the resume() method; and have onerror() throw

BREAKING CHANGE:

Sax had no default error handler but if you wanted to continue calling
``write()`` after an error you had to call ``resume()``. We do away with
``resume()`` and instead install a default ``onerror`` which throws. Replace
with a no-op handler if you want to continue after errors.

examples/example.js

@@ -11,9 +11,6 @@ const parser = saxes.parser();
 function inspector(ev) {
   return function handler(data) {
     console.error("%s %s %j", `${this.line}:${this.column}`, ev, data);
-    if (ev === "error") {
-      parser.resume();
-    }
   };
 }
 

lib/saxes.js

@@ -96,7 +96,7 @@ exports.EVENTS = [
 const buffers = [
   "comment", "openWakaBang", "textNode", "tagName", "doctype", "piTarget",
   "piBody", "entity", "attribName", "attribValue", "cdata", "xmlDeclName",
-  "xmlDeclValue"
+  "xmlDeclValue",
 ];
 
 let Stream;
@@ -142,7 +142,7 @@ class SAXParser {
     this.opt = opt || {};
     this.tags = [];
     this.closed = this.closedRoot = this.sawRoot = false;
-    this.tag = this.error = null;
+    this.tag = null;
     this.state = S_BEGIN;
     this.ENTITIES = Object.create(XML_ENTITIES);
     this.attribList = [];
@@ -188,11 +188,13 @@ class SAXParser {
   onopencdata() {}
   oncdata() {}
   onclosecdata() {}
-  onerror() {}
   onend() {}
   onready() {}
   onopennamespace() {}
   onclosenamespace() {}
+  onerror(err) {
+    throw new Error(err);
+  }
   /* eslint-enable class-methods-use-this */
 
   end() {
@@ -220,15 +222,11 @@ class SAXParser {
     const message = (this.trackPosition) ?
           `${this.fileName}:${this.line}:${this.column}: ${er}` : er;
 
-    this.error = er = new Error(message);
-    this.onerror(er);
+    this.onerror(new Error(message));
     return this;
   }
 
   write(chunk) {
-    if (this.error) {
-      throw this.error;
-    }
     if (this.closed) {
       return this.fail("cannot write after close; assign an onready handler.");
     }
@@ -1002,11 +1000,6 @@ class SAXParser {
     return this;
   }
 
-  resume() {
-    this.error = null;
-    return this;
-  }
-
   close() {
     return this.write(null);
   }
@@ -1316,10 +1309,6 @@ class SAXStream extends Stream {
 
     this._parser.onerror = (er) => {
       this.emit("error", er);
-
-      // if didn't throw, then means error was handled.
-      // go ahead and clear error, so we can write again.
-      this._parser.error = null;
     };
   }
 

test/index.js

@@ -27,7 +27,6 @@ exports.test = function test(options) {
 
         if (ev === "error") {
           expect([ev, n.message]).to.deep.equal(expected[expectedIx]);
-          parser.resume();
         }
         else {
           if (ev === "opentagstart" || ev === "opentag") {