chore: update type definitions for coverageReporters;

jestjs · Jul 14, 2020 · b057851 · b057851
1 parent 5fe8b08
commit b057851
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Showing 3 changed files with 19 additions and 4 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -19,6 +19,7 @@
 - `[jest-jasmine2]` Remove usage of `Function` type ([#10216](https://github.com/facebook/jest/pull/10216))
 - `[jest-resolve]` Improve types ([#10239](https://github.com/facebook/jest/pull/10239))
 - `[docs]` Clarify the [`jest.requireActual(moduleName)`](https://jestjs.io/docs/en/jest-object#jestrequireactualmodulename) example
+- `[jest-types]` Refine typings of `coverageReporters` ([#10275](https://github.com/facebook/jest/pull/10275))
 
 ### Performance
 

diff --git a/docs/Configuration.md b/docs/Configuration.md
@@ -193,7 +193,7 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
-### `coverageReporters` [array\<string | [string,any]>]
+### `coverageReporters` [CoverageReporters]
 
 Default: `["json", "lcov", "text", "clover"]`
 

diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
@@ -23,6 +23,20 @@ export type HasteConfig = {
   throwOnModuleCollision?: boolean;
 };
 
+export type CoverageReporterName = keyof ReportOptions;
+
+export type CoverageReporterWithOptions<
+  K = CoverageReporterName
+> = K extends CoverageReporterName
+  ? ReportOptions[K] extends never
+    ? never
+    : [K, Partial<ReportOptions[K]>]
+  : never;
+
+export type CoverageReporters = Array<
+  CoverageReporterName | CoverageReporterWithOptions
+>;
+
 export type ReporterConfig = [string, Record<string, unknown>];
 export type TransformerConfig = [string, Record<string, unknown>];
 
@@ -39,7 +53,7 @@ export type DefaultOptions = {
   clearMocks: boolean;
   collectCoverage: boolean;
   coveragePathIgnorePatterns: Array<string>;
-  coverageReporters: Array<string | [string, any]>;
+  coverageReporters: Array<CoverageReporterName>;
   coverageProvider: CoverageProvider;
   errorOnDeprecated: boolean;
   expand: boolean;
@@ -108,7 +122,7 @@ export type InitialOptions = Partial<{
   coverageDirectory: string;
   coveragePathIgnorePatterns: Array<string>;
   coverageProvider: CoverageProvider;
-  coverageReporters: Array<string>;
+  coverageReporters: CoverageReporters;
   coverageThreshold: {
     global: {
       [key: string]: number;
@@ -238,7 +252,7 @@ export type GlobalConfig = {
   coverageDirectory: string;
   coveragePathIgnorePatterns?: Array<string>;
   coverageProvider: CoverageProvider;
-  coverageReporters: Array<keyof ReportOptions | [keyof ReportOptions, any]>;
+  coverageReporters: CoverageReporters;
   coverageThreshold?: CoverageThreshold;
   detectLeaks: boolean;
   detectOpenHandles: boolean;