Variable nodes with nested variables report a parsing error, but work properly in the runtime

[mnojek]

Context

We have a rule in Robocop that parses non-local variables and checks if they are written in uppercase. I realized recently (thanks to the MarketSquare/robotframework-robocop#678) that we should exclude nested variables from the check, so that ${VAR${nested}} would not report a rule violation.

The bug

I realized that correct variables are marked with an error by RF Parsing API. For example, this code, run with robot --variable var1:1 test.robot:

*** Variables ***
${var${1}}    1

*** Test Cases ***
My Test
    Log To Console    ${var${1}}

executes with PASS state.

But when parsing the variable node, I see that there is an error there:

The bug appears in RF 5 and 6. I haven't tested for earlier versions.

Here are some more examples that raise the same error for RF Parsing API:

${MY_VAR${var}}  11
${MY VAR${VAR}}  11
${${var}MY VAR${VAR}}  11
${${var${VAR}}MY VAR${VAR}}  11
${@{VAR}[1]MY_VAR&{var.param}}  11
${${var${VAR}}my_var}  11
${${VAR}my_var}  11
${${VAR}my_var${var}}  11
${@{VAR}[1]my_var}  11
${@{VAR}[1]my_var&{var.param}}  11

[pekkaklarck]

Thanks for the report!