127 lines
3.2 KiB
Markdown
127 lines
3.2 KiB
Markdown
# Script data
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## Summary
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For legacy reasons, HTML comments can appear within a script tag, and if there is a `<script` in it, the first following `</script>` within the comment does **not** close the main script tag.
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minify-html does **not** do this special handling, as it adds complexity and slows down performance dramatically, for a legacy feature that is not recommended to be (and almost never) used.
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See https://www.w3.org/TR/html52/syntax.html#script-data-state for more details.
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Commit [20c59769](https://github.com/wilsonzlin/minify-html/commit/20c59769fea6bfb8a9d5ecea47d979dc9b1dcda5) removed support.
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## States and transitions
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|State|`<script`|`</script`|`<!--`|`-->`|
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|---|---|---|---|---|
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|Normal|-|End|Escaped|-|
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|Escaped|DoubleEscaped|End|-|Normal|
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|DoubleEscaped|-|Escaped|-|Normal|
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## Examples
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```html
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<script type="text/html">
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<script>
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exec1 = true;
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</script>
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<script>
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exec2 = true;
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</script>
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</script>
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```
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These are true about the above snippet:
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- `document.querySelectorAll('script').length === 2`.
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- `!window.exec1 && window.exec2`.
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- `document.querySelector('script[type="text/html"]')` has exactly one child node and it's a text node.
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If there is one or more `<script>` inside an HTML comment before any `</script>`, the first `</script>` will not end the main script.
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Ending tag inside comment works because there are no nested script tags.
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```html
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<script type="text/plain"><!--
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</script>
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```
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There is a nested tag but it doesn't need to be closed because it's treated as text.
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```html
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<script type="text/plain">
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<script>
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</script>
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```
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There is a nested tag but it doesn't need to be closed because it's not inside an HTML comment.
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```html
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<script type="text/plain">
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<script><!--
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</script>
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```
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There is a nested tag but it doesn't need to be closed because main closing tag is not inside an HTML comment.
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```html
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<script type="text/plain"><!--
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<script>-->
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</script>
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```
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The main closing tag is in a HTML comment but still works because there is no `<script>` before it in its comment (there is one in the previous comment).
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```html
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<script type="text/plain">
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<!--<script>--><!--
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</script>
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```
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There is a nested tag and it's in an HTML comment but it doesn't need to be closed because it's not `script`.
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```html
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<script type="text/plain"><!--
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<div>
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</script>
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```
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First closing tag is inside a comment with one or more previous opening tags so it doesn't close main script tag.
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```html
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<script type="text/plain"><!--
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<script>alert();</script>
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</script>
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```
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There is a nested tag and it needs to be closed because it's in a comment `script`. The amount of `<script>` doesn't matter.
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```html
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<script type="text/plain"><!--
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<script><script><script><script><script>alert();</script>
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</script>
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```
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First and second closing tags close their respective previous 1+ opening tags.
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```html
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<script type="text/plain"><!--
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<script><script><script>alert();</script>
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<script></script>
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</script>
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```
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Main closing tag works because it is in a separate comment.
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```html
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<script type="text/plain">
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<!--<script><script><script>--><!--
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</script>
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```
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Main closing tag works because it is not in a comment.
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```html
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<script type="text/plain">
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<!--<script>-->
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</script>
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```
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