How do I convert a variable name between snake_case, camelCase, and other styles in Vim?

Explanation

The vim-abolish plugin (by tpope) provides a cr (coerce) operator that converts the word under the cursor between naming conventions with a single keystroke pair. It understands snake_case, camelCase, MixedCase, UPPER_CASE, kebab-case, dot.case, and more — making it indispensable when refactoring variable names across different style conventions.

How it works

cr is followed by a letter specifying the target case:

• crs — snake_case
• crc — camelCase
• crm — MixedCase (PascalCase)
• cru — UPPER_CASE
• crk — kebab-case
• cr. — dot.case
• cr<Space> — space case
• crt — Title Case

Example

With the cursor on myVariableName:

crs → my_variable_name
cru → MY_VARIABLE_NAME
crk → my-variable-name
crm → MyVariableName
crc → myVariableName  (back to original)

Tips

• Install with any plugin manager: Plug 'tpope/vim-abolish'
• cr works on the word under the cursor — no need to visually select first
• vim-abolish also provides a powerful :Subvert command for case-aware substitution across a file
• Works well with the dot command (.) if you need to coerce the same pattern on multiple words