Add a Converter back to Javascript #154
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see also: jquery/esprima#2076 |
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This would be amazing! Are you basing this code on escodegen? https://github.com/estools/escodegen/blob/master/escodegen.js |
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no, but maybe that would be a good idea... |
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Esprima has the same JSON presentation as JS counterpart so I would think that parsing the program, creating JSON from it, feeding it to Jint as object and then evaluating the escodegen.js against it should produce the JS in question, at least in theory. |
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Yes, but I don't think I would do that. That would be much slower (at runtime) than converting escodegen to a c# classand using it. |
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@sebastienros would you think that should be a class in esprima-dotnet or should i create an extra github repo for it? |
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I think being able to write the javascript back is indeed a good thing, and quite often requested. |
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i'll work on this one again when the rest is merged 😊 |
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@lahma @sebastienros At the Moment this converter adds much to many brackets to the code. This could be optimized over time. |
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I assume you deserve some sleep now. |
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;-) it's only half past 1 in germany |
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@sebastienros @lahma I also think the visitor pattern is done wrong, we don't return the expressions, so I could not use the visitor to modify the tree. |
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I've merged my bigint pull here to, but I will rebase once it's merged. I need it cause or code uses BigInt |
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I think there also will be packages were the converter still will fail, but I've tested a few wich are in use in our application: jquery, jquery-ui, monaco editor, polymer3, fontawesome, cropperjs, dock-spwan-ts so most javascript should work atm. |
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@sebastienros @lahma |
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@sebastienros @lahma I've now fixed the coding to match esprima-net style, so I think this is ready for review |
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?? |
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| namespace Esprima.Utils | ||
| { | ||
| public static class ToJavascriptConverterExtension |
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Make it internal for now and add ToJavaScriptString() on Program.
The idea is that we parse, get an instance of Program (the parse tree) and can call ToJavaScriptString() on it directly, without having to deal with an alternate class.
Making it internal will let us change it later without breaking changes.
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If I do so, I need to copy the whole class to my Code, cause I use it to minify ES6 Template Literals with HTML & CSS inside, see:
public class BaseCustomWebcomponentMinifier : ToJavascriptConverter
{
public static string ToJavascript(Node node)
{
var visitor = new BaseCustomWebcomponentMinifier();
visitor.Visit(node);
return visitor.ToString();
}
protected override void VisitPropertyDefinition(PropertyDefinition propertyDefinition)
{
if (TryGetParentAt(1) is ClassBody && propertyDefinition.Static && propertyDefinition.Key is Identifier i)
{
if (i.Name == "style")
{
if (propertyDefinition.Value is TaggedTemplateExpression tte)
{
if (tte.Tag is Identifier iT && iT.Name=="css")
{
if (tte.Quasi is TemplateLiteral tl)
{
if (tl.Quasis.Count==1 && tl.Quasis[0] is TemplateElement)
{
var q = tl.Quasis[0];
var css = q.Value.Raw;
try
{
var parser = new CssParser();
var ss = parser.ParseStyleSheet(css);
var newCss = ss.ToCss(new AngleSharp.Css.MinifyStyleFormatter());
css = newCss;
}
catch (Exception ex)
{ }
_sb.Append("static style=css`" + css + "`;");
return;
}
}
}
}
}
if (i.Name == "template")
{
if (propertyDefinition.Value is TaggedTemplateExpression tte)
{
if (tte.Tag is Identifier iT && iT.Name == "html")
{
if (tte.Quasi is TemplateLiteral tl)
{
if (tl.Quasis.Count == 1 && tl.Quasis[0] is TemplateElement)
{
var q = tl.Quasis[0];
var html = q.Value.Raw;
try
{
var parser = new HtmlParser();
var h = parser.ParseDocument(html);
var newHtml = h.ToHtml(new AngleSharp.Html.MinifyMarkupFormatter());
html = newHtml;
}
catch (Exception ex)
{ }
_sb.Append("static template=html`" + html + "`;");
return;
}
}
}
}
}
}
base.VisitPropertyDefinition(propertyDefinition);
}
}
cause of that I also wanted to convert the Visitor to a real Visitor wich can return a modified AST
| var program = parser.ParseScript(); | ||
| var code = ToJavascriptConverter.ToJavascript(program); | ||
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| Assert.Equal("if(true){p();}switch(foo){case 'A':p();break;}switch(foo){default:p();break;}for(var a=[];;){}for(var elem of list){}", code); |
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This is the only test that actually checks the rendered javascript. Ideally any javavascript in should be the same out, but if we can't keep the original text because we should at least export with a common indentation pattern, and be able to check the output is fine. Maybe a better test in this case is to take any javascript file (call it source1), parse it, render it (call it source2) and ensure that parsing and rendering source2 is the same as source2.
This can be done for all subsequent tests in this file.
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I can fix the tests...
I many used them to test parts wich did not work, I will create an really expected output.
Of cause we need indention on the converter (if beautification is enabled), but I had no time atm to work on this.
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Is it generating valid JavaScript?
_sb.Append("static style=css`" + css + "`;");
If so, could you update the parse tree before it's rendered to JS instead?
If not then we'll have to live with this class being public for now. Or you could do some InternalVisibleFrom trick.
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yes
i could not update the tree, cause everthing is readonly
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cause of that I wanted a real visitor pattern like the ExpressionVisitor in C#, wich could return modified Expressions
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I can do the changes I requested if you want me to help. |
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@sebastienros I did now a simple beautification. |
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@sebastienros hello, sorry to be impatient, but any more issues with this or could it be merged? |
| @@ -67,6 +66,30 @@ public static AssignmentOperator ParseAssignmentOperator(string op) | |||
| }; | |||
| } | |||
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| public static string ConvertAssignmentOperator(AssignmentOperator op) | |||
| @@ -84,6 +84,39 @@ public static BinaryOperator ParseBinaryOperator(string op) | |||
| }; | |||
| } | |||
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| public static string ConvertBinaryOperator(BinaryOperator op) | |||
| @@ -50,6 +50,23 @@ private static UnaryOperator ParseUnaryOperator(string? op) | |||
| }; | |||
| } | |||
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| public static string ConvertUnaryOperator(UnaryOperator op) | |||
| } | ||
| } | ||
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| public class ToJavascriptConverter |
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is this implementation details, like internal sealed, would name like JavascriptWriter or something like so make more sense?
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Maybe we should resurrect this one, and schedule for v3? This needs a rebase and maybe a peer review from @adams85 (if you have time for it). |
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When the ast refactoring is merged, I'll look to rebase this |
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Sure, I'll take a look at it after rebase has been done. |
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i've rebase this branch in #291 |
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