Type 'T' does not satisfy the constraint 'SignalRef...

[Maxim-Mazurok]

Please:

• Check for duplicate issues. Please file separate requests as separate issues.
• Describe how to reproduce the bug.
• Use the latest versions of Vega and Vega-Lite.
• Provide an minimal, reproducible example
• If applicable, include error messages and screenshots, GIF videos (e.g. using https://www.cockos.com/licecap/), or working examples (e.g. by clicking share in the Vega-Editor or https://bit.ly/vega-lite-blocks)

When running npx tsc --noEmit I'm getting this error:

node_modules/vega-lite/build/src/channeldef.d.ts:63:66 - error TS2344: Type 'T' does not satisfy the constraint 'SignalRef | ExprRef | FieldDef<any, any> | DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue> | ValueDef<...>'.
  Type 'T' is not assignable to type 'DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue>'.

63 export declare function isConditionalParameter<T>(c: Conditional<T>): c is ConditionalParameter<T>;
                                                                    ~

  node_modules/vega-lite/build/src/channeldef.d.ts:63:48
    63 export declare function isConditionalParameter<T>(c: Conditional<T>): c is ConditionalParameter<T>;
                                                      ~
    This type parameter might need an `extends DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue>` constraint.
  node_modules/vega-lite/build/src/channeldef.d.ts:63:48
    63 export declare function isConditionalParameter<T>(c: Conditional<T>): c is ConditionalParameter<T>;
                                                      ~
    This type parameter might need an `extends SignalRef | ExprRef | FieldDef<any, any> | DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue> | ValueDef<...>` constraint.

node_modules/vega-lite/build/src/channeldef.d.ts:63:97 - error TS2344: Type 'T' does not satisfy the constraint 'SignalRef | ExprRef | FieldDef<any, any> | DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue> | ValueDef<...>'.

63 export declare function isConditionalParameter<T>(c: Conditional<T>): c is ConditionalParameter<T>;
                                                                                                   ~

  node_modules/vega-lite/build/src/channeldef.d.ts:63:48
    63 export declare function isConditionalParameter<T>(c: Conditional<T>): c is ConditionalParameter<T>;
                                                      ~
    This type parameter might need an `extends SignalRef | ExprRef | FieldDef<any, any> | DatumDef<string, SignalRef | DateTime | ExprRef | PrimitiveValue> | ValueDef<...>` constraint.


Found 2 errors in the same file, starting at: node_modules/vega-lite/build/src/channeldef.d.ts:63

My tsconfig:

{
  "compilerOptions": {
    "target": "ES2015",
    "moduleResolution": "Node",
    "strict": true,
    "esModuleInterop": true,
    "types": ["jest", "node"],
    "lib": ["ESNext", "DOM"]
  }
}

(notice "strict: true", without it compiles fine)

[domoritz]

Is this a duplicate of #5477?

[Maxim-Mazurok]

Yeah, it seems to compile fine with

"strict": true,
"strictNullChecks": false,

So I guess it is the same issue indeed.

I'm just using "skipLibCheck": true for now as a workaround