Dev mode update and reload behavior

Keep iteration fast by knowing which changes apply instantly and which require a restart. Extension.js chooses the lightest safe update mode per file change.

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Update modes

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Common examples

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What to do when you need to restart

When Extension.js reports Restart required, stop and rerun extension dev before continuing. Typical triggers:

• Adding or removing manifest entrypoint references
• Adding or removing files under pages/ or scripts/ used as extension entrypoints
• Structural script/style entry changes in HTML entrypoints

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Practical guidance

• Prefer editing existing modules/assets during active dev sessions for fastest feedback.
• Batch structural manifest changes (entrypoint list edits) so you restart once.
• Treat restart required diagnostics as authoritative; continuing without restart can leave your runtime in a stale state.

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Next steps

• manifest.json
• content scripts
• background scripts / service worker
• HTML