SimpleChatTCRV:MarkDown:Cleanup overall initial go

Save copy of data being processed.

Try and sanitize the data passed for markdown to html conversion,
so that if there are any special characters wrt html in the passed
markdown content, it gets translated into a harmless text.

This also ensures that those text dont disappear, bcas of browser
trying to interpret them as html tagged content.

Trap any errors during sanitizing and or processing of the lines
in general and push them into a errors array. Callers of this
markdown class can decide whether to use the converted html or
not based on errors being empty or not or ...

Move the processing of unordered list into a function of its own.
Rather the ordered list can also use the same flow in general except
for some tiny changes including wrt the regex, potentially.

tools/server/public_simplechat/typemd.mjs

@@ -25,7 +25,11 @@ export class MarkDown {
             /** @type {Array<number>} */
             listUnordered: []
         }
-        this.md = ""
+        /**
+         * @type {Array<*>}
+         */
+        this.errors = []
+        this.raw = ""
         this.html = ""
     }
 
@@ -40,6 +44,48 @@ export class MarkDown {
         this.unwind_list_unordered()
     }
 
+    /**
+     * Process a unordered list one line at a time
+     * @param {string} line
+     */
+    process_list_unordered(line) {
+        // spaces followed by - or + or * followed by a space and actual list item
+        let matchUnOrdered = line.match(/^([ ]*)[-+*][ ](.*)$/);
+        if (matchUnOrdered != null) {
+            let sList = 'none'
+            let listLvl = 0
+            if (this.in.listUnordered.length == 0) {
+                sList = 'same'
+                this.in.listUnordered.push(matchUnOrdered[1].length)
+                listLvl = this.in.listUnordered.length // ie 1
+                this.html += "<ul>\n"
+            } else {
+                if (this.in.listUnordered[this.in.listUnordered.length-1] < matchUnOrdered[1].length){
+                    sList = 'same'
+                    this.in.listUnordered.push(matchUnOrdered[1].length)
+                    listLvl = this.in.listUnordered.length
+                    this.html += "<ul>\n"
+                } else if (this.in.listUnordered[this.in.listUnordered.length-1] == matchUnOrdered[1].length){
+                    sList = 'same'
+                } else {
+                    sList = 'same'
+                    while (this.in.listUnordered[this.in.listUnordered.length-1] > matchUnOrdered[1].length) {
+                        this.in.listUnordered.pop()
+                        this.html += `</ul>\n`
+                        if (this.in.listUnordered.length == 0) {
+                            break
+                        }
+                    }
+                }
+            }
+            if (sList == 'same') {
+                this.html += `<li>${matchUnOrdered[2]}</li>\n`
+            }
+            return true
+        }
+        return false
+    }
+
     /**
      * Try extract a table from markdown content, one line at a time.
      * This is a imperfect logic, but should give a rough semblance of a table many a times.
@@ -102,6 +148,9 @@ export class MarkDown {
      * @param {string} line
      */
     process_line(line) {
+        let elSanitize = document.createElement('div')
+        elSanitize.textContent = line
+        line = elSanitize.innerHTML
         let lineA = line.split(' ')
         if (this.in.preFenced.length > 0) {
             if (line == this.in.preFenced) {
@@ -137,38 +186,7 @@ export class MarkDown {
             this.html += `<pre class="${matchPreFenced[2]}">\n`
             return
         }
-        // spaces followed by - or + or * followed by a space and actual list item
+        if (this.process_list_unordered(line)) {
-        let matchUnOrdered = line.match(/^([ ]*)[-+*][ ](.*)$/);
-        if ( matchUnOrdered != null) {
-            let sList = 'none'
-            let listLvl = 0
-            if (this.in.listUnordered.length == 0) {
-                sList = 'same'
-                this.in.listUnordered.push(matchUnOrdered[1].length)
-                listLvl = this.in.listUnordered.length // ie 1
-                this.html += "<ul>\n"
-            } else {
-                if (this.in.listUnordered[this.in.listUnordered.length-1] < matchUnOrdered[1].length){
-                    sList = 'same'
-                    this.in.listUnordered.push(matchUnOrdered[1].length)
-                    listLvl = this.in.listUnordered.length
-                    this.html += "<ul>\n"
-                } else if (this.in.listUnordered[this.in.listUnordered.length-1] == matchUnOrdered[1].length){
-                    sList = 'same'
-                } else {
-                    sList = 'same'
-                    while (this.in.listUnordered[this.in.listUnordered.length-1] > matchUnOrdered[1].length) {
-                        this.in.listUnordered.pop()
-                        this.html += `</ul>\n`
-                        if (this.in.listUnordered.length == 0) {
-                            break
-                        }
-                    }
-                }
-            }
-            if (sList == 'same') {
-                this.html += `<li>${matchUnOrdered[2]}</li>\n`
-            }
             return
         }
         this.unwind_list()
@@ -180,9 +198,14 @@ export class MarkDown {
      * @param {string} lines
      */
     process(lines) {
+        this.raw = lines
         let linesA = lines.split('\n')
         for(const line of linesA) {
-            this.process_line(line)
+            try {
+                this.process_line(line)
+            } catch (err) {
+                this.errors.push(err)
+            }
         }
     }