[MDCTheme] Theme.Property mixin not correctly using theme keys (primary, secondary, etc.)

[aisgbnok]

Bug report

When attempting to use the theme.property mixin with an MDC Theme key (primary, secondary, etc.) the build fails.
However theme.prop which is now deprecated works correctly.

Steps to reproduce

1. Use theme.property mixin with MDC Theme key (primary, secondary, etc.)
   Example: @include theme.property(border-color, primary);
2. See error

Actual behavior

The build fails with output:

SassError: Undefined variable.
   ╷
94 │     $custom-prop: custom-properties.create(--mdc-theme-#{$style}, $fallback);
   │                                                          ^^^^^^
   ╵
  node_modules\@material\theme\_mixins.scss 94:58  property()

Expected behavior

theme.property will correctly use MDC Theme keys with output:

border-color: #6200EE;
border-color: var(--mdc-theme-primary, #6200EE);

when using @include theme.property(border-color, primary);

Environment:

Software	Version(s)
MDC Web	7.0.0
Browser	Chrome 83
Operating System	Windows 10 (2004)

[allan-chen]

Hi Anthony,

Thanks for filing the issue - it seems that $style may need to be $value instead - adding @asyncLiz to confirm.

[asyncLiz]

Confirmed!