Merge pull request microsoft#9090 from weswigham/allow-empty-lists-command-line

Allow empty lists on command line

Author: weswigham

src/compiler/commandLineParser.ts

@@ -493,13 +493,20 @@ namespace ts {
     }
 
     /* @internal */
-    export function parseListTypeOption(opt: CommandLineOptionOfListType, value: string, errors: Diagnostic[]): (string | number)[] {
-        const values = trimString((value || "")).split(",");
+    export function parseListTypeOption(opt: CommandLineOptionOfListType, value = "", errors: Diagnostic[]): (string | number)[] | undefined {
+        value = trimString(value);
+        if (startsWith(value, "-")) {
+            return undefined;
+        }
+        if (value === "") {
+            return [];
+        }
+        const values = value.split(",");
         switch (opt.element.type) {
             case "number":
-                return ts.map(values, parseInt);
+                return map(values, parseInt);
             case "string":
-                return ts.map(values, v => v || "");
+                return map(values, v => v || "");
             default:
                 return filter(map(values, v => parseCustomTypeOption(<CommandLineOptionOfCustomType>opt.element, v, errors)), v => !!v);
         }
@@ -560,8 +567,11 @@ namespace ts {
                                     i++;
                                     break;
                                 case "list":
-                                    options[opt.name] = parseListTypeOption(<CommandLineOptionOfListType>opt, args[i], errors);
-                                    i++;
+                                    const result = parseListTypeOption(<CommandLineOptionOfListType>opt, args[i], errors);
+                                    options[opt.name] = result || [];
+                                    if (result) {
+                                        i++;
+                                    }
                                     break;
                                 // If not a primitive, the possible types are specified in what is effectively a map of options.
                                 default:

tests/cases/unittests/commandLineParsing.ts

@@ -216,10 +216,23 @@ namespace ts {
                         file: undefined,
                         start: undefined,
                         length: undefined,
-                    }, {
-                        messageText: "Argument for '--lib' option must be:  'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'dom', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory'",
-                        category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
-                        code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
+                    }],
+                    fileNames: ["0.ts"],
+                    options: {
+                        lib: []
+                    }
+                });
+        });
+
+        it("Parse empty string of --lib ", () => {
+            // 0.ts --lib
+            // This test is an error because the empty string is falsey
+            assertParseResult(["0.ts", "--lib", ""],
+                {
+                    errors: [{
+                        messageText: "Compiler option 'lib' expects an argument.",
+                        category: ts.Diagnostics.Compiler_option_0_expects_an_argument.category,
+                        code: ts.Diagnostics.Compiler_option_0_expects_an_argument.code,
 
                         file: undefined,
                         start: undefined,
@@ -232,6 +245,19 @@ namespace ts {
                 });
         });
 
+        it("Parse immediately following command line argument of --lib ", () => {
+            // 0.ts --lib
+            assertParseResult(["0.ts", "--lib", "--sourcemap"],
+                {
+                    errors: [],
+                    fileNames: ["0.ts"],
+                    options: {
+                        lib: [],
+                        sourceMap: true
+                    }
+                });
+        });
+
         it("Parse --lib option with extra comma ", () => {
             // --lib es5, es7 0.ts
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],