How devtools map minified JS code back to your TypeScript source code

Recent related post where Apple seemingly forgot to disable source maps for the App Store

Apple's App Store Full Front End Source Code

https://news.ycombinator.com/item?id=45804664

edit: formatting

kayson 2 days ago | parent | prev | next [-]

I love it when things are displayed so nicely on mobile. This could've been a pain to read and get through but it was actually quite pleasant.

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tantalor 2 days ago | parent | prev | next [-]

> Notice how the decoded values give relative positions, each value represents the difference from the previous position, not absolute coordinates. This is crucial: instead of encoding large column numbers like 27698 in minified files, source maps only store small deltas like +7 or +15, making the encoded strings much more compact.

Wouldn't "offset" be a more apt term?

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manojvivek 2 days ago | parent | next [-]

To me, “offset” sounds more like the distance from the start, whereas here the values are relative to the previous segment. Not a native english speaker, so I could be wrong.

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tantalor 2 days ago | parent [-]

Offset is difference from a starting point or a previous position

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jagged-chisel 2 days ago | parent [-]

“Offset” is not enough on its own. Offset from what? Start of file? Absolute offset. Previous offset? Relative offset.

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willrshansen 2 days ago | parent [-]

2nd order offset. The offset from the <offset from the start of the file>

	▲	eat_veggies 2 days ago \| parent [-]
		perhaps the delta between offsets

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hanikesn 2 days ago | parent | prev | next [-]

Delta Encoding is the common term

	▲	tracker1 2 days ago \| parent [-]
		Agreed... Delta Encoding, or even Delta Offset would work together.

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accrual 2 days ago | parent | prev | next [-]

In this case I feel it's like six of one and a half-dozen of the other.

Delta definition 4: (mathematics, physics, engineering) The symbol Δ; A change in a quantity, likely from "d" for "difference"

Offset definition 7: The distance by which one thing is out of alignment with another.

Got these from Wiktionary:

* https://en.wiktionary.org/wiki/delta

* https://en.wiktionary.org/wiki/offset

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recursive 2 days ago | parent | prev | next [-]

It sounds equally apt to my ear. I've used both words for this concept in the past.

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paulddraper 2 days ago | parent | prev [-]

Delta and offset mean the same thing — the difference between two amounts.

Delta is perhaps slightly more obscure outside of a math setting. Perhaps.

	▲	saghm a day ago \| parent [-]
		I feel like choosing the synonym that happens to be one letter shorter when the operation is literally intended to track things in a way that's more conscise is about as "apt" as it could be!

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zb3 2 days ago | parent | prev [-]

Tangentially related, but last year I've made a tool to recover original sources from web apps which expose source maps (with the sourcesContent value present), including enumerating all lazily loaded chunks:

https://github.com/zb3/getfrontend