diff --git a/src/handler/hover.ts b/src/handler/hover.ts
index 3a71af1a0af..d4a9a7170ab 100644
--- a/src/handler/hover.ts
+++ b/src/handler/hover.ts
@@ -121,6 +121,8 @@ export default class HoverHandler {
     const defs = await this.handler.withRequestToken('definitionHover', token => {
       return languages.getDefinitionLinks(doc.textDocument, position, token)
     }, false)
+    // could be cancelled
+    if (defs == null) return false
     await addDefinitions(hovers, defs, doc.filetype)
     let hover = hovers.find(o => Hover.is(o) && Range.is(o.range)) as Hover | undefined
     if (hover?.range) {
diff --git a/src/handler/locations.ts b/src/handler/locations.ts
index 3d29c72c6c6..43bbc9d95b0 100644
--- a/src/handler/locations.ts
+++ b/src/handler/locations.ts
@@ -10,6 +10,7 @@ import { hasOwnProperty } from '../util/object'
 import { CancellationToken, CancellationTokenSource } from '../util/protocol'
 import workspace from '../workspace'
 import { HandlerDelegate } from './types'
+import { isFalsyOrEmpty } from '../util/array'
 
 export interface TagDefinition {
   name: string
@@ -77,7 +78,7 @@ export default class LocationsHandler {
       return languages.getDefinition(doc, position, token)
     })
     await this.handleLocations(definition, openCommand)
-    return definition ? definition.length > 0 : false
+    return !isFalsyOrEmpty(definition)
   }
 
   public async gotoDeclaration(openCommand?: string | false): Promise<boolean> {
@@ -85,7 +86,7 @@ export default class LocationsHandler {
       return languages.getDeclaration(doc, position, token)
     })
     await this.handleLocations(definition, openCommand)
-    return definition ? definition.length > 0 : false
+    return !isFalsyOrEmpty(definition)
   }
 
   public async gotoTypeDefinition(openCommand?: string | false): Promise<boolean> {
@@ -93,7 +94,7 @@ export default class LocationsHandler {
       return languages.getTypeDefinition(doc, position, token)
     })
     await this.handleLocations(definition, openCommand)
-    return definition ? definition.length > 0 : false
+    return !isFalsyOrEmpty(definition)
   }
 
   public async gotoImplementation(openCommand?: string | false): Promise<boolean> {
@@ -101,7 +102,7 @@ export default class LocationsHandler {
       return languages.getImplementation(doc, position, token)
     })
     await this.handleLocations(definition, openCommand)
-    return definition ? definition.length > 0 : false
+    return !isFalsyOrEmpty(definition)
   }
 
   public async gotoReferences(openCommand?: string | false, includeDeclaration = true): Promise<boolean> {
@@ -109,7 +110,7 @@ export default class LocationsHandler {
       return languages.getReferences(doc, { includeDeclaration }, position, token)
     })
     await this.handleLocations(definition, openCommand)
-    return definition ? definition.length > 0 : false
+    return !isFalsyOrEmpty(definition)
   }
 
   public async getTagList(): Promise<TagDefinition[] | null> {
diff --git a/src/handler/selectionRange.ts b/src/handler/selectionRange.ts
index 9f06acbd728..58ef28d87ed 100644
--- a/src/handler/selectionRange.ts
+++ b/src/handler/selectionRange.ts
@@ -17,10 +17,9 @@ export default class SelectionRangeHandler {
     let { doc, position } = await this.handler.getCurrentState()
     this.handler.checkProvider(ProviderName.SelectionRange, doc.textDocument)
     await doc.synchronize()
-    let selectionRanges: SelectionRange[] = await this.handler.withRequestToken('selection ranges', token => {
+    return await this.handler.withRequestToken('selection ranges', token => {
       return languages.getSelectionRanges(doc.textDocument, [position], token)
     })
-    return selectionRanges
   }
 
   public async selectRange(visualmode: string, forward: boolean): Promise<boolean> {
diff --git a/src/handler/typeHierarchy.ts b/src/handler/typeHierarchy.ts
index e523f7bd2c2..897d3803edb 100644
--- a/src/handler/typeHierarchy.ts
+++ b/src/handler/typeHierarchy.ts
@@ -114,7 +114,7 @@ export default class TypeHierarchyHandler {
     return res
   }
 
-  private async prepare(doc: TextDocument, position: Position): Promise<TypeHierarchyItem[] | undefined> {
+  private async prepare(doc: TextDocument, position: Position): Promise<TypeHierarchyItem[] | undefined | null> {
     this.handler.checkProvider(ProviderName.TypeHierarchy, doc)
     return await this.handler.withRequestToken('typeHierarchy', async token => {
       return await languages.prepareTypeHierarchy(doc, position, token)