Compiler [tooling.compiler]
config.nims
Use config.nims to harden your build by promoting selected warnings (and hints) to errors, forcing safer, cleaner code to pass compilation.
A config.nims snippet which can be copy/pasted follows; it converts certain compile-time warnings and hints to errors.
# turn warnings into compile errors
switch("warningAsError", "BareExcept:on")
switch("warningAsError", "CaseTransition:on")
switch("warningAsError", "CStringConv:on")
switch("warningAsError", "ImplicitDefaultValue:on")
switch("warningAsError", "LongLiterals:on")
switch("warningAsError", "ResultShadowed:on")
switch("warningAsError", "UnreachableCode:on")
switch("warningAsError", "UnreachableElse:on")
switch("warningAsError", "UnusedImport:on")
switch("warningAsError", "UseBase:on")
# turn hints into compile errors
switch("hintAsError", "ConvFromXtoItselfNotNeeded:on")
switch("hintAsError", "DuplicateModuleImport:on")
switch("hintAsError", "XCannotRaiseY:on")
Some of these hints or warnings, such as XCannotRaiseY, might prove situationally impractical to enforce as errors; these can be omitted as required.
Scope of config.nims
A library’s config.nims file usually does not affect projects that depend on the library. It is typically applied only when the library itself is the active project or when the library is included as a subdirectory of another project.
This is generally beneficial: it allows the library’s own CI and development setup to use stricter checks without causing unexpected effects in downstream projects.