vue codemirror 取消autoFormatRange后如何做json格式化

方法一：JSON.stringify

this.codemirror.setValue((JSON.stringify(JSON.parse(jsonStr), null, 2)))

缺点：这样会造成数值类型值的精度丢失，如:

{
  "a":1.000000000000000000,
  "b":123455667111111111117
}

{a: 1, b: 123455667111111110000}

方法二：autoFormatRange

CodeMirror.defineExtension("autoFormatRange", function (from, to) {
    var cm = this;
    var outer = cm.getMode(), text = cm.getRange(from, to).split("\n");
    var state = CodeMirror.copyState(outer, cm.getTokenAt(from).state);
    var tabSize = cm.getOption("tabSize");

    var out = "", lines = 0, atSol = from.ch == 0;
    function newline() {
        out += "\n";
        atSol = true;
        ++lines;
    }

    for (var i = 0; i < text.length; ++i) {
        var stream = new CodeMirror.StringStream(text[i], tabSize);
        while (!stream.eol()) {
            var inner = CodeMirror.innerMode(outer, state);
            var style = outer.token(stream, state), cur = stream.current();
            stream.start = stream.pos;
            if (!atSol || /\S/.test(cur)) {
                out += cur;
                atSol = false;
            }
            if (!atSol && inner.mode.newlineAfterToken &&
                inner.mode.newlineAfterToken(style, cur, stream.string.slice(stream.pos) || text[i+1] || "", inner.state))
                newline();
        }
        if (!stream.pos && outer.blankLine) outer.blankLine(state);
        if (!atSol) newline();
    }

    cm.operation(function () {
        cm.replaceRange(out, from, to);
        for (var cur = from.line + 1, end = from.line + lines; cur <= end; ++cur)
            cm.indentLine(cur, "smart");
    });
});

// Applies automatic mode-aware indentation to the specified range
CodeMirror.defineExtension("autoIndentRange", function (from, to) {
    var cmInstance = this;
    this.operation(function () {
        for (var i = from.line; i <= to.line; i++) {
            cmInstance.indentLine(i, "smart");
        }
    });
});

<textarea id=code><?=$value?></textarea>

<link rel="stylesheet" href="/codemirror/codemirror.css">
<script src="/codemirror/codemirror-compressed.js"></script>
<script>
var editor = CodeMirror.fromTextArea(document.getElementById('code'), {
    lineNumbers: true,
    mode: "text/html"
});
var totalLines = editor.lineCount();  
editor.autoFormatRange({line:0, ch:0}, {line:totalLines});
</script>

方法三：js-beautify

const beautify_js = require('js-beautify').js_beautify
const formattedJSON = beautify_js(jsonStr, { indent_size: 2 })
this.codemirror.setValue(formattedJSON)