fix(types): Add TypeScript definitions for status flags (#595)

TanStack · Jun 22, 2020 · 007b9b4 · 007b9b4
1 parent 5291ed7
commit 007b9b4
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Showing 3 changed files with 72 additions and 0 deletions.
diff --git a/types/index.d.ts b/types/index.d.ts
@@ -370,6 +370,9 @@ export type QueryStatus = 'idle' | 'loading' | 'error' | 'success'
 export interface QueryResultBase<TResult, TError = Error> {
   status: QueryStatus
   error: null | TError
+  isLoading: boolean
+  isSuccess: boolean
+  isError: boolean
   isFetching: boolean
   isStale: boolean
   failureCount: number
@@ -379,19 +382,28 @@ export interface QueryResultBase<TResult, TError = Error> {
 export interface QueryLoadingResult<TResult, TError = Error>
   extends QueryResultBase<TResult, TError> {
   status: 'loading'
+  isLoading: true
+  isSuccess: false
+  isError: false
   data: TResult | undefined // even when error, data can have stale data
   error: TError | null // it still can be error
 }
 
 export interface QueryErrorResult<TResult, TError = Error>
   extends QueryResultBase<TResult, TError> {
   status: 'error'
+  isError: true
+  isLoading: false
+  isSuccess: false
   data: TResult | undefined // even when error, data can have stale data
   error: TError
 }
 
 export interface QuerySuccessResult<TResult> extends QueryResultBase<TResult> {
   status: 'success'
+  isSuccess: true
+  isLoading: false
+  isError: false
   data: TResult
   error: null
 }
@@ -404,6 +416,9 @@ export type QueryResult<TResult, TError = Error> =
 export interface PaginatedQueryLoadingResult<TResult, TError = Error>
   extends QueryResultBase<TResult, TError> {
   status: 'loading'
+  isLoading: true
+  isError: false
+  isSuccess: false
   resolvedData: undefined | TResult // even when error, data can have stale data
   latestData: undefined | TResult // even when error, data can have stale data
   error: null | TError // it still can be error
@@ -412,6 +427,9 @@ export interface PaginatedQueryLoadingResult<TResult, TError = Error>
 export interface PaginatedQueryErrorResult<TResult, TError = Error>
   extends QueryResultBase<TResult, TError> {
   status: 'error'
+  isError: true
+  isLoading: false
+  isSuccess: false
   resolvedData: undefined | TResult // even when error, data can have stale data
   latestData: undefined | TResult // even when error, data can have stale data
   error: TError
@@ -420,6 +438,9 @@ export interface PaginatedQueryErrorResult<TResult, TError = Error>
 export interface PaginatedQuerySuccessResult<TResult>
   extends QueryResultBase<TResult> {
   status: 'success'
+  isSuccess: true
+  isError: false
+  isLoading: false
   resolvedData: TResult
   latestData: TResult
   error: null

diff --git a/types/test.ts b/types/test.ts
@@ -182,6 +182,25 @@ function paginatedQuery() {
     queryPaginated.latestData // $ExpectType { data: number[]; next: boolean; }
     queryPaginated.error // $ExpectType null
   }
+
+  // Discriminated union over status flags
+  if (queryPaginated.isLoading) {
+    queryPaginated.resolvedData // $ExpectType { data: number[]; next: boolean; } | undefined
+    queryPaginated.latestData // $ExpectType { data: number[]; next: boolean; } | undefined
+    queryPaginated.error // $ExpectType Error | null
+  }
+
+  if (queryPaginated.isError) {
+    queryPaginated.resolvedData // $ExpectType { data: number[]; next: boolean; } | undefined
+    queryPaginated.latestData // $ExpectType { data: number[]; next: boolean; } | undefined
+    queryPaginated.error // $ExpectType Error
+  }
+
+  if (queryPaginated.isSuccess) {
+    queryPaginated.resolvedData // $ExpectType { data: number[]; next: boolean; }
+    queryPaginated.latestData // $ExpectType { data: number[]; next: boolean; }
+    queryPaginated.error // $ExpectType null
+  }
 }
 
 function paginatedQueryWithObjectSyntax(condition: boolean) {
@@ -412,6 +431,24 @@ function dataDiscriminatedUnion() {
     queryResult.data // $ExpectType string[]
     queryResult.error // $ExpectType null
   }
+
+  // Discriminated union over status flags
+  if (queryResult.isLoading) {
+    queryResult.data // $ExpectType string[] | undefined
+    queryResult.error // $ExpectType Error | null
+  }
+
+  if (queryResult.isError) {
+    // disabled
+    queryResult.data // $ExpectType string[] | undefined
+    queryResult.error // $ExpectType Error
+  }
+
+  if (queryResult.isSuccess) {
+    // disabled
+    queryResult.data // $ExpectType string[]
+    queryResult.error // $ExpectType null
+  }
 }
 
 function mutationStatusDiscriminatedUnion() {

diff --git a/yarn.lock b/yarn.lock
@@ -358,6 +358,11 @@
   resolved "https://registry.yarnpkg.com/@babel/helper-validator-identifier/-/helper-validator-identifier-7.10.1.tgz#5770b0c1a826c4f53f5ede5e153163e0318e94b5"
   integrity sha512-5vW/JXLALhczRCWP0PnFDMCJAchlBvM7f4uk/jXritBnIa6E1KmqmtrS3yn1LAnxFBypQ3eneLuXjsnfQsgILw==
 
+"@babel/helper-validator-identifier@^7.10.3":
+  version "7.10.3"
+  resolved "https://registry.yarnpkg.com/@babel/helper-validator-identifier/-/helper-validator-identifier-7.10.3.tgz#60d9847f98c4cea1b279e005fdb7c28be5412d15"
+  integrity sha512-bU8JvtlYpJSBPuj1VUmKpFGaDZuLxASky3LhaKj3bmpSTY6VWooSM8msk+Z0CZoErFye2tlABF6yDkT3FOPAXw==
+
 "@babel/helper-wrap-function@^7.10.1":
   version "7.10.1"
   resolved "https://registry.yarnpkg.com/@babel/helper-wrap-function/-/helper-wrap-function-7.10.1.tgz#956d1310d6696257a7afd47e4c42dfda5dfcedc9"
@@ -404,6 +409,15 @@
     chalk "^2.0.0"
     js-tokens "^4.0.0"
 
+"@babel/highlight@^7.8.3":
+  version "7.10.3"
+  resolved "https://registry.yarnpkg.com/@babel/highlight/-/highlight-7.10.3.tgz#c633bb34adf07c5c13156692f5922c81ec53f28d"
+  integrity sha512-Ih9B/u7AtgEnySE2L2F0Xm0GaM729XqqLfHkalTsbjXGyqmf/6M0Cu0WpvqueUlW+xk88BHw9Nkpj49naU+vWw==
+  dependencies:
+    "@babel/helper-validator-identifier" "^7.10.3"
+    chalk "^2.0.0"
+    js-tokens "^4.0.0"
+
 "@babel/parser@^7.1.0", "@babel/parser@^7.7.4":
   version "7.7.4"
   resolved "https://registry.npmjs.org/@babel/parser/-/parser-7.7.4.tgz#75ab2d7110c2cf2fa949959afb05fa346d2231bb"