在JavaScript中处理和过滤具有相似模式的大字符串

Question

I have a thousands line of chrome console log with the similar pattern as below.

10:52:52.041 VM757:15 __popover4
10:52:52.041 VM757:16 Error: dummy
    at fnClass._createPopover (ColorPicker.js:339)
    at fnClass.init (ColorPicker.js:127)
    at fnClass.constructor (ManagedObject-dbg.js?eval:451)
    at fnClass.constructor (Element-dbg.js?eval:99)
    at fnClass.constructor (Control-dbg.js?eval:103)
10:52:52.041 VM757:15 __layout331
10:52:52.042 VM757:16 Error: dummy
    at fnClass.constructor (ManagedObject-dbg.js?eval:385)
    at fnClass.constructor (Element-dbg.js?eval:99)
    at fnClass.constructor (Control-dbg.js?eval:103)
    at new fnClass (Metadata-dbg.js?eval:346)
10:52:52.042 VM757:15 __chooser4
10:52:52.042 VM757:16 Error: dummy

What I want to do is that, between two 10:52:52, if the string contains a key word: color (eg. ColorPicker.js), remove the part of the string from the first of "10:52:52" to the end "10:52:52". for example, because bellowing string contains key word color, the whole string should be removed.

10:52:52.041 VM757:16 Error: dummy
    at fnClass._createPopover (ColorPicker.js:339)
    at fnClass.init (ColorPicker.js:127)
    at fnClass.constructor (ManagedObject-dbg.js?eval:451)
    at fnClass.constructor (Element-dbg.js?eval:99)
    at fnClass.constructor (Control-dbg.js?eval:103)
10:52:52.041 VM757:15 __layout331

then the manipulated remaining string is:

10:52:52.041 VM757:15 __popover4
10:52:52.042 VM757:16 Error: dummy
    at fnClass.constructor (ManagedObject-dbg.js?eval:385)
    at fnClass.constructor (Element-dbg.js?eval:99)
    at fnClass.constructor (Control-dbg.js?eval:103)
    at new fnClass (Metadata-dbg.js?eval:346)
10:52:52.042 VM757:15 __chooser4
10:52:52.042 VM757:16 Error: dummy

To be more specifically, this is my pseudo-code:

var sOriginal = import log file;
while(sOriginal is not reach the end){
    var bShouldBeRemoved = false;
    var bStartedPointFound = false;
    if(bStartedPointFound == false && string match "10:52:52"){
        mark it as the start point;
        bStartedPointFound = true;
        while(!string reach the next "10:52:52" || !reach end of the string){
            if(string contains "color"){
                bShouldBeRemoved = true;
            }
        }
        if(bShouldBeRemoved === true){
            remove the part of the string from the first "10:52:52"
        }
    }
}

return sResult

Answer 1

First of all, you will need to break the log into blocks, you can split your string by line break, and then iterate over the given array. After you got an array of lines, you will need to split each line and decide if it belongs to some block or not.

Whenever you will have an array of block you can search your keyword and if found, remove the block.

 const log = `10:52:52.041 VM757:15 __popover4 10:52:52.041 VM757:16 Error: dummy at fnClass._createPopover (ColorPicker.js:339) at fnClass.init (ColorPicker.js:127) at fnClass.constructor (ManagedObject-dbg.js?eval:451) at fnClass.constructor (Element-dbg.js?eval:99) at fnClass.constructor (Control-dbg.js?eval:103) 10:52:52.041 VM757:15 __layout331 10:52:52.042 VM757:16 Error: dummy at fnClass.constructor (ManagedObject-dbg.js?eval:385) at fnClass.constructor (Element-dbg.js?eval:99) at fnClass.constructor (Control-dbg.js?eval:103) at new fnClass (Metadata-dbg.js?eval:346) 10:52:52.042 VM757:15 __chooser4 10:52:52.042 VM757:16 Error: dummy`; function cleanLog(log, term) { const lines = log.split("\\n"); const blocks = lines.reduce((acc, line) => { if (/^\\d+:\\d+/.test(line)) { acc.push([line]); } else { acc[acc.length - 1].push(line); } return acc; }, []); return blocks.filter((block) => block.join('').indexOf(term) === -1) } console.log(cleanLog(log, 'Color'));