You can use these regular expressions and replacement expressions inside your favorite editor when you need to unify your YAML file to use double quote for all strings.
For example converting:
key1: value 1
key2: 'value 2'
key3: 'value "3"'
To:
key1: "value 1"
key2: "value 2"
key3: "value \"3\""
The first lines are the regex to find and the last lines are the replace expressions.
Convert single quoted values to double in YAML
:(\s?)'(.*)'
:$1"$2"
e.g. key: 'value'
will be converted to key: "value"
Escape double quotes inside double quoted strings in YAML
:(\s?)"(.*)([^\\])"(.*)"
:$1"$2$3\\"$4"
Needs to be run multiple times until no match is found.
e.g. key: "field "name" is empty"
will be converted to key: "field \"name\" is empty"