Bug: Expanding snippets over a region.

[jasonm23]

Given an auto-snippet which is defined that uses a special yasnippet form (${n:...}) for example when a field has implicit casing rules.

When it is expanded over a region and the special form is on $1

Then it will expand incorrectly.

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Triage / root cause summary

During aya-expand if a region is detected the following happens.

• The region is saved, to str
• In the current snippet. The parameter $1 is replaced with $0. This allows the snippet to expand and place the cursor at $0 when the expansion is complete.
• The str string is then inserted at point.

In the cases where $1 is a special form, the replacement doesn't happen as planned and this breaks the expansion.

Potential solutions.

YASnippet provides a mechanim for working with a selected region, yas-selected-text and (yas-selected-text)

• use (yas-selected-text) instead using our hand-rolled save / insert region

• check for optional { when modifying the exit field to be $0 (so it'll be ${0...)

• [x] make this operation a testable function

• [x] Add tests

[jasonm23]

Fixed in these commits.

c2fcbc149204800fadb57592d4db96f12d55471c

854b1018df044a3df14fb2b83fb058e2c2dc1183

f8bdb785adf4ce364196ee98e93325df22bcf385

850e44f0e1b3a5678590216a98a6c8f3101b2772

5b86d94637249ebf820ec94b8bfb47d6561fa369

c5507344e1ba7ddbce6d755823c2f8503f9e28b4

66c01fd0874c47acccd98992a6cab3a4beca8fd1