gatsby-link: add withPrefix to index.d.ts #2887
Description
Recently the gatsby-link withPrefix helper was added. It would be helpful to have this also added to gatsby-link's index.d.ts, so this function could be used in typescript.
-------------- contributing side note --------------
In following the contributing guidelines, I downloaded a latest forked Gatsby source, ran yarn run bootstrap, and then ran tests locally before making modifications, which turned up eight tests failures out of the box. I see that some recent PR test run jobs #4773.1 and #4773.2 have also exhibited the same failures on Travis. Are these test failures common? If so, what is the associated issue and the recommended procedure for resolving them?
Summary of all failing tests
FAIL packages/gatsby/cache-dir/__tests__/loader.js
● Loader › You can enqueue paths
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can enqueue paths
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:21:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › FIFO by default
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › FIFO by default
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:27:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Paths enqueued more times are prioritized
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Paths enqueued more times are prioritized
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:33:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Paths are only added once to the queue
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Paths are only added once to the queue
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:40:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can't enqueue paths that don't exist
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can't enqueue paths that don't exist
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:50:19)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can dequeue a path
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can dequeue a path
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:54:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can get the order of a path
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › You can get the order of a path
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:59:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Resources are ordered correctly by count
TypeError: loader.empty is not a function
at Object.beforeEach (packages/gatsby/cache-dir/__tests__/loader.js:5:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
● Loader › Resources are ordered correctly by count
TypeError: loader.enqueue is not a function
at Object.test (packages/gatsby/cache-dir/__tests__/loader.js:65:12)
at Promise (<anonymous>)
at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)