Fix getting CLI version

In case CLI prints other things (like warnings from loading extensions) to its stdout, the `nativescript-doctor` returns incorrect version for CLI.
Fix this by getting only the version from stdout.
Add unit tests for this scenario.

Author: rosen-vladimirov

lib/sys-info.ts

@@ -298,7 +298,7 @@ export class SysInfo implements NativeScriptDoctor.ISysInfo {
 	public getNativeScriptCliVersion(): Promise<string> {
 		return this.getValueForProperty(() => this.nativeScriptCliVersionCache, async (): Promise<string> => {
 			const output = await this.execCommand("tns --version");
-			return output ? output.trim() : output;
+			return output ? this.getVersionFromString(output.trim()) : output;
 		});
 	}
 

test/sys-info.ts

@@ -126,7 +126,7 @@ function mockSysInfo(childProcessResult: IChildProcessResults, hostInfoOptions?:
 		spawnFromEvent: async (command: string, args: string[], event: string, options: ISpawnFromEventOptions) => {
 			return getResultFromChildProcess(childProcessResultDictionary[command], command, options);
 		},
-		execFile: async () => {
+		execFile: async (): Promise<any> => {
 			return undefined;
 		}
 	};
@@ -322,6 +322,29 @@ describe("SysInfo unit tests", () => {
 			});
 		});
 
+		describe("nativeScriptCliVersion", () => {
+			it("is null when tns is not installed", async () => {
+				childProcessResult.nativeScriptCliVersion = { shouldThrowError: true };
+				sysInfo = mockSysInfo(childProcessResult, { isWindows: false, isDarwin: true, dotNetVersion: "4.5.1" });
+				let result = await sysInfo.getSysInfo();
+				assert.deepEqual(result.nativeScriptCliVersion, null);
+			});
+
+			it("is correct when the version is the only row in `tns --version` output", async () => {
+				childProcessResult.nativeScriptCliVersion = { result: setStdOut("3.0.0") };
+				sysInfo = mockSysInfo(childProcessResult, { isWindows: false, isDarwin: true, dotNetVersion: "4.5.1" });
+				let result = await sysInfo.getSysInfo();
+				assert.deepEqual(result.nativeScriptCliVersion, "3.0.0");
+			});
+
+			it("is correct when there are warnings in the `tns --version` output", async () => {
+				childProcessResult.nativeScriptCliVersion = { result: setStdOut("Some warning due to invalid extensions\\n3.0.0") };
+				sysInfo = mockSysInfo(childProcessResult, { isWindows: false, isDarwin: true, dotNetVersion: "4.5.1" });
+				let result = await sysInfo.getSysInfo();
+				assert.deepEqual(result.nativeScriptCliVersion, "3.0.0");
+			});
+		});
+
 		describe("returns correct results when exceptions are raised during sysInfo data collection", () => {
 			beforeEach(() => {
 				childProcessResult = {