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javascriptnode.jsmarkdownjavascript-marked

Convert between Markdown elements

What are the options to parse Markdown document and process its elements to output an another Markdown document?

Let's say it

```
# unaffected #
```

# H1 #

H1
==

## H2 ##

H2
--

### H3 ###

should be converted to

```
# unaffected #
```

## H1 ##

H1
--

### H2 ###

### H2 ###

#### H3 ####

in Node environment. Target element may vary (e.g. #### may be converted to **).

The document may contain other markup elements that should remain unaffected.

How it can be obtained? Obviously, not with regexps (using regexp instead of full-blown lexer will affect # unaffected #). I was hoped to use marked but it seems that it is capable only of HTML output, not Markdown.

Solution

  • Have you considered using HTML as an intermediate format? Once in HTML, the differences between the header types will be indistinguishable, so the Markdown -> HTML conversion will effectively normalize them for you. There are markdown -> HTML converters aplenty, and also a number of HTML -> markdown.

    I put together an example using these two packages:

    I don't know if you have any performance requirements here (read: this is slow...) but this is a very low investment solution. Take a look:

    var md = require('markdown-it')(),
    h2m = require('h2m');

var mdContent = `
\`\`\`
# unaffected #
\`\`\`

# H1 #

H1
==

## H2 ##

H2
--

### H3 ###
`;

var htmlContent = md.render(mdContent);
var newMdContent = h2m(htmlContent, {converter: 'MarkdownExtra'});
console.log(newMdContent);

    You may have to play with a mix of components to get the correct dialect support and whatnot. I tried a bunch and couldn't quite match your output. I think perhaps the -- is being interpreted differently? Here's the output, I'll let you decide if it is good enough:

    ```
# unaffected #

```

# H1 #

# H1 #

## H2 ##

## H2 ##

### H3 ###