Allow comments in tsconfig.json issue #4987

tests/cases/unittests/tsconfigParsing.ts

@@ -0,0 +1,84 @@
+/// <reference path="..\..\..\src\harness\harness.ts" />
+/// <reference path="..\..\..\src\compiler\commandLineParser.ts" />
+
+module ts {
+  describe('parseConfigFileTextToJson', () => {
+    function assertParseResult(jsonText: string, expectedConfigObject: { config?: any; error?: Diagnostic }) {
+      let parsed = ts.parseConfigFileTextToJson("/apath/tsconfig.json", jsonText);
+      assert.equal(JSON.stringify(parsed), JSON.stringify(expectedConfigObject));
+    }
+    
+    function assertParseError(jsonText: string) {     
+       let parsed = ts.parseConfigFileTextToJson("/apath/tsconfig.json", jsonText);
+       assert.isTrue(undefined === parsed.config);    
+       assert.isTrue(undefined !== parsed.error);     
+    }
+
+    it("returns empty config for file with only whitespaces", () => {
+    	assertParseResult("", { config : {} });
+      assertParseResult(" ", { config : {} });
+    });
+    
+    it("returns empty config for file with comments only", () => {
+      assertParseResult("// Comment", { config: {} });
+      assertParseResult("# Comment", { config: {} });
+      assertParseResult("/* Comment*/", { config: {} });
+    });
+
+    it("returns empty config when config is empty object", () => {
+      assertParseResult("{}", { config: {} });
+    });
+
+    it("returns config object without comments", () => {
+      assertParseResult(
+      	`{ // Excluded files
+      		"exclude": [
+  					// Exclude d.ts
+  					"file.d.ts"
+  				]
+      	}`, { config: { exclude: ["file.d.ts"] } });
+      assertParseResult(
+        `{
+      		# Excluded files
+      		"exclude": [
+  					# Exclude d.ts
+  					"file.d.ts"
+  				]
+      	}`, { config: { exclude: ["file.d.ts"] } });
+      assertParseResult(
+        `{
+      		/* Excluded
+      			 Files
+      		*/
+      		"exclude": [  		
+  					/* multiline comments can be in the middle of a line */"file.d.ts"
+  				]
+      	}`, { config: { exclude: ["file.d.ts"] } });
+    });
+
+    it("keeps string content untouched", () => {
+      assertParseResult(
+        `{
+      		"exclude": [
+  					"xx//file.d.ts"
+  				]
+      	}`, { config: { exclude: ["xx//file.d.ts"] } });
+      assertParseResult(
+        `{
+      		"exclude": [
+  					"xx#file.d.ts"
+  				]
+      	}`, { config: { exclude: ["xx#file.d.ts"] } });
+      assertParseResult(
+        `{
+      		"exclude": [
+  					"xx/*file.d.ts*/"
+  				]
+      	}`, { config: { exclude: ["xx/*file.d.ts*/"] } });
+    });
+    
+    it("returns object with error when json is invalid", () => {
+       assertParseError("invalid");      
+    });
+  });
+}