Ab/duplicate results

src/index.ts

@@ -394,7 +394,8 @@ interface CourseSearchResult {
    * default form action will be prevented.
    */
   onSubmit: (e: PreventableEvent) => void
-  from: number
+  from: number 
+  searchAfter: Array<number> | null
   updateUI: (newUI: string | null) => void
   ui: string | null
 }
@@ -405,7 +406,8 @@ export const useCourseSearch = (
     searchFacets: Facets,
     nextFrom: number,
     sort?: SortParam | null,
-    ui?: string | null
+    ui?: string | null,
+    searchAfter?: Array<number> | null
   ) => Promise<void>,
   clearSearch: () => void,
   aggregations: Aggregations,
@@ -415,6 +417,7 @@ export const useCourseSearch = (
 ): CourseSearchResult => {
   const [incremental, setIncremental] = useState(false)
   const [from, setFrom] = useState(0)
+  const [searchAfter, setSearchAfter] = useState(null)
 
   const seachUI = useSearchInputs(history)
   const {
@@ -454,7 +457,8 @@ export const useCourseSearch = (
       if (!incremental) {
         clearSearch()
         nextFrom = 0
-      }
+      } 
+
       setFrom(nextFrom)
       setIncremental(incremental)
 
@@ -472,13 +476,15 @@ export const useCourseSearch = (
         searchFacets.type = LR_TYPE_ALL
       }
 
-      await runSearch(text, searchFacets, nextFrom, sort, ui)
+      await runSearch(text, searchFacets, nextFrom, sort, ui, searchAfter)
 
       setLocation(history, { text, activeFacets, sort, ui })
     },
     [
       from,
       setFrom,
+      searchAfter,
+      setSearchAfter,
       setIncremental,
       clearSearch,
       runSearch,
@@ -589,6 +595,7 @@ export const useCourseSearch = (
     onSubmit,
     from,
     updateUI,
-    ui
+    ui,
+    searchAfter
   }
 }

src/search.ts

@@ -148,12 +148,13 @@ export const normalizeDoubleQuotes = (
 export const emptyOrNil = either(isEmpty, isNil)
 
 /**
-  Interface for parameters for generating a search query. Supported fields are text, from, size, sort, channelName
+  Interface for parameters for generating a search query. Supported fields are text, searchAfter, size, sort, channelName
   and activeFacets. activeFacets supports audience, certification, type, offered_by, topics, department_name, level,
   course_feature_tags and resource_type as nested params
 */
 export interface SearchQueryParams {
   text?: string
+  searchAfter?: number[]
   from?: number
   size?: number
   sort?: SortParam
@@ -176,6 +177,7 @@ const getTypes = (activeFacets: Facets | undefined) => {
 */
 export const buildSearchQuery = ({
   text,
+  searchAfter,
   from,
   size,
   sort,
@@ -186,12 +188,15 @@ export const buildSearchQuery = ({
 }: SearchQueryParams): Record<string, any> => {
   let builder = bodybuilder()
 
-  if (!isNil(from)) {
-    builder = builder.from(from)
+  if (!isNil(searchAfter)) {
+    builder = builder.rawOption("search_after", searchAfter)
   }
   if (!isNil(size)) {
     builder = builder.size(size)
   }
+  if (isNil(searchAfter) && !isNil(from)) {
+    builder = builder.from(from)
+  }
   if (
     sort &&
     activeFacets &&
@@ -290,6 +295,8 @@ export const buildLearnQuery = (
   facets?: Facets,
   aggregations?: Array<string>
 ): Record<string, any> => {
+  let orSubqueriesBuilder = bodybuilder()
+
   for (const type of types) {
     const queryType = isDoubleQuoted(text) ? "query_string" : "multi_match"
     const textQuery = emptyOrNil(text) ?
@@ -348,24 +355,60 @@ export const buildLearnQuery = (
 
     // Add filters for facets if necessary
     const facetClauses = buildFacetSubQuery(facets, builder, type, aggregations)
-    builder = buildOrQuery(builder, type, textQuery, [])
+
+    if (!emptyOrNil(text)) {
+      orSubqueriesBuilder = buildOrQuery(
+        orSubqueriesBuilder,
+        type,
+        textQuery,
+        []
+      )
+    } else {
+      builder = buildOrQuery(builder, type, textQuery, [])
+    }
+
     builder = builder.rawOption("post_filter", {
       bool: {
         must: [...facetClauses]
       }
     })
 
-    // Include suggest if search test is not null/empty
-    if (!emptyOrNil(text)) {
-      builder = builder.rawOption(
-        "suggest",
-        // @ts-expect-error
-        buildSuggestQuery(text, LEARN_SUGGEST_FIELDS)
-      )
-    } else if (facetClauses.length === 0 && equals(types, LR_TYPE_ALL)) {
+    if (
+      emptyOrNil(text) &&
+      facetClauses.length === 0 &&
+      equals(types, LR_TYPE_ALL)
+    ) {
       builder = builder.rawOption("sort", buildDefaultSort())
     }
   }
+
+  if (!emptyOrNil(text)) {
+    builder = builder.rawOption(
+      "suggest",
+      // @ts-expect-error
+      buildSuggestQuery(text, LEARN_SUGGEST_FIELDS)
+    )
+
+    builder = builder.query("function_score", {
+      boost_mode:   "replace",
+      script_score: {
+        script: {
+          source: "Math.round(_score*2)"
+        }
+      },
+      ...orSubqueriesBuilder.build()
+    })
+
+    builder = builder.rawOption("sort", [
+      {
+        _score: "desc"
+      },
+      {
+        created: "desc"
+      }
+    ])
+  }
+
   return builder.build()
 }