diff --git a/extensions/emmet/src/abbreviationActions.ts b/extensions/emmet/src/abbreviationActions.ts
index 0224594a33e..1a372ced9d3 100644
--- a/extensions/emmet/src/abbreviationActions.ts
+++ b/extensions/emmet/src/abbreviationActions.ts
@@ -88,9 +88,9 @@ export function wrapIndividualLinesWithAbbreviation(args: any) {
 
 }
 
-export function expandEmmetAbbreviation(args: any): Thenable<boolean> {
+export function expandEmmetAbbreviation(args: any): Thenable<boolean | undefined> | undefined {
 	const syntax = getSyntaxFromArgs(args);
-	if (!syntax || !validate()) {
+	if (!syntax || !validate() || !vscode.window.activeTextEditor) {
 		return fallbackTab();
 	}
 
@@ -108,7 +108,7 @@ export function expandEmmetAbbreviation(args: any): Thenable<boolean> {
 	let allAbbreviationsSame: boolean = true;
 	const helper = getEmmetHelper();
 
-	let getAbbreviation = (document: vscode.TextDocument, selection: vscode.Selection, position: vscode.Position, syntax: string): [vscode.Range, string, string] => {
+	let getAbbreviation = (document: vscode.TextDocument, selection: vscode.Selection, position: vscode.Position, syntax: string): [vscode.Range | null, string, string] => {
 		let rangeToReplace: vscode.Range = selection;
 		let abbr = document.getText(rangeToReplace);
 		if (!rangeToReplace.isEmpty) {
diff --git a/extensions/emmet/src/test/abbreviationAction.test.ts b/extensions/emmet/src/test/abbreviationAction.test.ts
index 0f599e37b86..1c27174b28c 100644
--- a/extensions/emmet/src/test/abbreviationAction.test.ts
+++ b/extensions/emmet/src/test/abbreviationAction.test.ts
@@ -7,7 +7,13 @@ import 'mocha';
 import * as assert from 'assert';
 import { Selection, workspace } from 'vscode';
 import { withRandomFileEditor, closeAllEditors } from './testUtils';
-import { expandEmmetAbbreviation, wrapWithAbbreviation, wrapIndividualLinesWithAbbreviation } from '../abbreviationActions';
+import { expandEmmetAbbreviation as expandEmmetAbbreviationImpl, wrapWithAbbreviation, wrapIndividualLinesWithAbbreviation } from '../abbreviationActions';
+
+function expandEmmetAbbreviation(args): Thenable<boolean | undefined> {
+	const result = expandEmmetAbbreviationImpl(args);
+	assert.ok(result);
+	return result!;
+}
 
 const cssContents = `
 .boo {
diff --git a/extensions/emmet/src/test/incrementDecrement.test.ts b/extensions/emmet/src/test/incrementDecrement.test.ts
index e1c039dffca..afdde2b64e5 100644
--- a/extensions/emmet/src/test/incrementDecrement.test.ts
+++ b/extensions/emmet/src/test/incrementDecrement.test.ts
@@ -7,7 +7,13 @@ import 'mocha';
 import * as assert from 'assert';
 import { Selection } from 'vscode';
 import { withRandomFileEditor, closeAllEditors } from './testUtils';
-import { incrementDecrement } from '../incrementDecrement';
+import { incrementDecrement as incrementDecrementImpl } from '../incrementDecrement';
+
+function incrementDecrement(delta): Thenable<boolean> {
+	const result = incrementDecrementImpl(delta);
+	assert.ok(result);
+	return result!;
+}
 
 suite('Tests for Increment/Decrement Emmet Commands', () => {
 	teardown(closeAllEditors);
diff --git a/extensions/emmet/src/test/reflectCssValue.test.ts b/extensions/emmet/src/test/reflectCssValue.test.ts
index 3967503b676..5a905da6e6c 100644
--- a/extensions/emmet/src/test/reflectCssValue.test.ts
+++ b/extensions/emmet/src/test/reflectCssValue.test.ts
@@ -7,7 +7,13 @@ import 'mocha';
 import * as assert from 'assert';
 import { Selection } from 'vscode';
 import { withRandomFileEditor, closeAllEditors } from './testUtils';
-import { reflectCssValue } from '../reflectCssValue';
+import { reflectCssValue as reflectCssValueImpl } from '../reflectCssValue';
+
+function reflectCssValue(): Thenable<boolean> {
+	const result = reflectCssValueImpl();
+	assert.ok(result);
+	return result!;
+}
 
 suite('Tests for Emmet: Reflect CSS Value command', () => {
 	teardown(closeAllEditors);
diff --git a/extensions/emmet/src/test/tagActions.test.ts b/extensions/emmet/src/test/tagActions.test.ts
index c95bf8064bc..fa4f680cd18 100644
--- a/extensions/emmet/src/test/tagActions.test.ts
+++ b/extensions/emmet/src/test/tagActions.test.ts
@@ -45,7 +45,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(5, 35, 5, 35), // cursor inside closing tag
 			];
 
-			return updateTag('section').then(() => {
+			return updateTag('section')!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -71,7 +71,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(5, 35, 5, 35), // cursor inside closing tag
 			];
 
-			return removeTag().then(() => {
+			return removeTag()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -95,7 +95,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(7, 5, 7, 5), // split tag
 			];
 
-			return splitJoinTag().then(() => {
+			return splitJoinTag()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -138,7 +138,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(2, 3, 2, 3)
 			];
 
-			return mergeLines().then(() => {
+			return mergeLines()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -153,7 +153,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(5, 5, 5, 20) // selection spans multiple nodes in the same line
 			];
 
-			return mergeLines().then(() => {
+			return mergeLines()!.then(() => {
 				assert.equal(doc.getText(), contents);
 				return Promise.resolve();
 			});
diff --git a/extensions/emmet/src/test/toggleComment.test.ts b/extensions/emmet/src/test/toggleComment.test.ts
index 7423a028d4b..46adb42a8d5 100644
--- a/extensions/emmet/src/test/toggleComment.test.ts
+++ b/extensions/emmet/src/test/toggleComment.test.ts
@@ -7,7 +7,13 @@ import 'mocha';
 import * as assert from 'assert';
 import { Selection } from 'vscode';
 import { withRandomFileEditor, closeAllEditors } from './testUtils';
-import { toggleComment } from '../toggleComment';
+import { toggleComment as toggleCommentImpl } from '../toggleComment';
+
+function toggleComment(...args): Thenable<boolean> {
+	const result = toggleCommentImpl(...args);
+	assert.ok(result);
+	return result!;
+}
 
 suite('Tests for Toggle Comment action from Emmet (HTML)', () => {
 	teardown(closeAllEditors);
diff --git a/extensions/emmet/src/test/updateImageSize.test.ts b/extensions/emmet/src/test/updateImageSize.test.ts
index cc23e3f6651..c265a88a053 100644
--- a/extensions/emmet/src/test/updateImageSize.test.ts
+++ b/extensions/emmet/src/test/updateImageSize.test.ts
@@ -54,7 +54,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(11, 50, 11, 50)
 			];
 
-			return updateImageSize().then(() => {
+			return updateImageSize()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -111,7 +111,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(13, 50, 13, 50)
 			];
 
-			return updateImageSize().then(() => {
+			return updateImageSize()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
@@ -140,7 +140,7 @@ suite('Tests for Emmet actions on html tags', () => {
 				new Selection(4, 50, 4, 50)
 			];
 
-			return updateImageSize().then(() => {
+			return updateImageSize()!.then(() => {
 				assert.equal(doc.getText(), expectedContents);
 				return Promise.resolve();
 			});
diff --git a/extensions/emmet/src/toggleComment.ts b/extensions/emmet/src/toggleComment.ts
index e15dbd0c984..ce63584ff76 100644
--- a/extensions/emmet/src/toggleComment.ts
+++ b/extensions/emmet/src/toggleComment.ts
@@ -34,7 +34,7 @@ export function toggleComment(): Thenable<boolean> | undefined {
 
 	return editor.edit(editBuilder => {
 		editor.selections.reverse().forEach(selection => {
-			let edits = toggleCommentInternal(editor.document, selection, rootNode);
+			let edits = toggleCommentInternal(editor.document, selection, rootNode!);
 			edits.forEach(x => {
 				editBuilder.replace(x.range, x.newText);
 			});