Support full path for -project/-p paramater

src/compiler/diagnosticMessages.json

@@ -1622,7 +1622,7 @@
     },
     "Cannot assign an abstract constructor type to a non-abstract constructor type.": {
         "category": "Error",
-        "code":2517
+        "code": 2517
     },
     "Duplicate identifier '{0}'. Compiler uses declaration '{1}' to support async functions.": {
         "category": "Error",
@@ -2068,6 +2068,14 @@
         "category": "Error",
         "code": 5056
     },
+    "Cannot find a tsconfig.json file at the specified directory: '{0}'": {
+        "category": "Error",
+        "code": 5057
+    },
+    "The specified path does not exist: '{0}'": {
+        "category": "Error",
+        "code": 5058
+    },
 
     "Concatenate and emit output to single file.": {
         "category": "Message",

src/compiler/tsc.ts

@@ -295,11 +295,26 @@ namespace ts {
                 reportDiagnostic(createCompilerDiagnostic(Diagnostics.The_current_host_does_not_support_the_0_option, "--project"), /* compilerHost */ undefined);
                 return sys.exit(ExitStatus.DiagnosticsPresent_OutputsSkipped);
             }
-            configFileName = normalizePath(combinePaths(commandLine.options.project, "tsconfig.json"));
             if (commandLine.fileNames.length !== 0) {
                 reportDiagnostic(createCompilerDiagnostic(Diagnostics.Option_project_cannot_be_mixed_with_source_files_on_a_command_line), /* compilerHost */ undefined);
                 return sys.exit(ExitStatus.DiagnosticsPresent_OutputsSkipped);
             }
+
+            const fileOrDirectory = normalizePath(commandLine.options.project);
+            if (!fileOrDirectory /* current directory "." */ || sys.directoryExists(fileOrDirectory)) {
+                configFileName = combinePaths(fileOrDirectory, "tsconfig.json");
+                if (!sys.fileExists(configFileName)) {
+                    reportDiagnostic(createCompilerDiagnostic(Diagnostics.Cannot_find_a_tsconfig_json_file_at_the_specified_directory_Colon_0, commandLine.options.project), /* compilerHost */ undefined);
+                    return sys.exit(ExitStatus.DiagnosticsPresent_OutputsSkipped);
+                }
+            }
+            else {
+                configFileName = fileOrDirectory;
+                if (!sys.fileExists(configFileName)) {
+                    reportDiagnostic(createCompilerDiagnostic(Diagnostics.The_specified_path_does_not_exist_Colon_0, commandLine.options.project), /* compilerHost */ undefined);
+                    return sys.exit(ExitStatus.DiagnosticsPresent_OutputsSkipped);
+                }
+            }
         }
         else if (commandLine.fileNames.length === 0 && isJSONSupported()) {
             const searchPath = normalizePath(sys.getCurrentDirectory());