Include additional query values when interpolating href

packages/next/client/page-loader.ts

@@ -216,7 +216,7 @@ export default class PageLoader {
 
     const isDynamic: boolean = isDynamicRoute(route)
     const interpolatedRoute = isDynamic
-      ? interpolateAs(hrefPathname, asPathname, query)
+      ? interpolateAs(hrefPathname, asPathname, query).result
       : ''
 
     return isDynamic

packages/next/next-server/lib/router/router.ts

@@ -98,8 +98,10 @@ export function interpolateAs(
     query
 
   interpolatedRoute = route
+  const params = Object.keys(dynamicGroups)
+
   if (
-    !Object.keys(dynamicGroups).every((param) => {
+    !params.every((param) => {
       let value = dynamicMatches[param] || ''
       const { repeat, optional } = dynamicGroups[param]
 
@@ -129,7 +131,21 @@ export function interpolateAs(
     // n.b. We ignore this error because we handle warning for this case in
     // development in the `<Link>` component directly.
   }
-  return interpolatedRoute
+  return {
+    params,
+    result: interpolatedRoute,
+  }
+}
+
+function omitParmsFromQuery(query: ParsedUrlQuery, params: string[]) {
+  const filteredQuery: ParsedUrlQuery = {}
+
+  Object.keys(query).forEach((key) => {
+    if (!params.includes(key)) {
+      filteredQuery[key] = query[key]
+    }
+  })
+  return filteredQuery
 }
 
 /**
@@ -157,11 +173,16 @@ export function resolveHref(
     ) {
       const query = searchParamsToUrlQuery(finalUrl.searchParams)
 
-      interpolatedAs = interpolateAs(
+      const { result, params } = interpolateAs(
         finalUrl.pathname,
         finalUrl.pathname,
         query
       )
+      interpolatedAs = formatWithValidation({
+        pathname: result,
+        hash: finalUrl.hash,
+        query: omitParmsFromQuery(query, params),
+      })
     }
 
     // if the origin didn't change, it means we received a relative href
@@ -608,7 +629,7 @@ export default class Router implements BaseRouter {
     resolvedAs = delBasePath(resolvedAs)
 
     if (isDynamicRoute(route)) {
-      const { pathname: asPathname } = parseRelativeUrl(resolvedAs)
+      const { pathname: asPathname, ...parsedAs } = parseRelativeUrl(resolvedAs)
       const routeRegex = getRouteRegex(route)
       const routeMatch = getRouteMatcher(routeRegex)(asPathname)
       if (!routeMatch) {
@@ -632,7 +653,13 @@ export default class Router implements BaseRouter {
           )
         }
       } else if (route === asPathname) {
-        as = interpolateAs(route, asPathname, query)
+        const { result, params } = interpolateAs(route, asPathname, query)
+        as = formatWithValidation(
+          Object.assign({}, parsedAs, {
+            pathname: result,
+            query: omitParmsFromQuery(query, params),
+          })
+        )
       } else {
         // Merge params into `query`, overwriting any specified in search
         Object.assign(query, routeMatch)

test/integration/dynamic-routing/pages/[name]/index.js

@@ -3,7 +3,12 @@ import { useRouter } from 'next/router'
 const Page = () => {
   const router = useRouter()
   const { query } = router
-  return <p id="asdf">This is {query.name}</p>
+  return (
+    <>
+      <p id="asdf">This is {query.name}</p>
+      <p id="query">{JSON.stringify(query)}</p>
+    </>
+  )
 }
 
 Page.getInitialProps = () => ({})

test/integration/dynamic-routing/pages/index.js

@@ -31,6 +31,17 @@ const Page = () => {
         <a id="view-post-1-interpolated">View post 1 (interpolated)</a>
       </Link>
       <br />
+      <Link
+        href={{
+          pathname: '/[name]',
+          query: { name: 'post-1', another: 'value' },
+        }}
+      >
+        <a id="view-post-1-interpolated-more-query">
+          View post 1 (interpolated additional query)
+        </a>
+      </Link>
+      <br />
       <Link href="/[name]/comments" as="/post-1/comments">
         <a id="view-post-1-comments">View post 1 comments</a>
       </Link>

test/integration/dynamic-routing/test/index.test.js

@@ -153,7 +153,9 @@ function runTests(dev) {
         .elementByCss('#view-post-1-interpolated')
         .getAttribute('href')
 
-      expect(url.parse(href).pathname).toBe('/post-1')
+      const parsedHref = url.parse(href, true)
+      expect(parsedHref.pathname).toBe('/post-1')
+      expect(parsedHref.query).toEqual({})
 
       await browser.elementByCss('#view-post-1-interpolated').click()
       await browser.waitForElementByCss('#asdf')
@@ -167,6 +169,38 @@ function runTests(dev) {
     }
   })
 
+  it('should navigate to a dynamic page successfully interpolated with additional query values', async () => {
+    let browser
+    try {
+      browser = await webdriver(appPort, '/')
+      await browser.eval('window.beforeNav = 1')
+
+      const href = await browser
+        .elementByCss('#view-post-1-interpolated-more-query')
+        .getAttribute('href')
+
+      const parsedHref = url.parse(href, true)
+      expect(parsedHref.pathname).toBe('/post-1')
+      expect(parsedHref.query).toEqual({ another: 'value' })
+
+      await browser.elementByCss('#view-post-1-interpolated-more-query').click()
+      await browser.waitForElementByCss('#asdf')
+
+      expect(await browser.eval('window.beforeNav')).toBe(1)
+
+      const text = await browser.elementByCss('#asdf').text()
+      expect(text).toMatch(/this is.*?post-1/i)
+
+      const query = JSON.parse(await browser.elementByCss('#query').text())
+      expect(query).toEqual({
+        name: 'post-1',
+        another: 'value',
+      })
+    } finally {
+      if (browser) await browser.close()
+    }
+  })
+
   it('should allow calling Router.push on mount successfully', async () => {
     const browser = await webdriver(appPort, '/post-1/on-mount-redir')
     try {