Make processDiagnosticMessages.ts generate a module

(Also improve the generated comment at the top.)

Author: elibarzilay

scripts/processDiagnosticMessages.ts

@@ -38,10 +38,7 @@ function main(): void {
         }
     }
 
-    const outputFilesDir = path.dirname(inputFilePath);
-    const thisFilePathRel = path.relative(process.cwd(), outputFilesDir);
-
-    const infoFileOutput = buildInfoFileOutput(diagnosticMessages, "./diagnosticInformationMap.generated.ts", thisFilePathRel);
+    const infoFileOutput = buildInfoFileOutput(diagnosticMessages, inputFilePath);
     checkForUniqueCodes(diagnosticMessages);
     writeFile("diagnosticInformationMap.generated.ts", infoFileOutput);
 
@@ -59,28 +56,31 @@ function checkForUniqueCodes(diagnosticTable: InputDiagnosticMessageTable) {
     });
 }
 
-function buildInfoFileOutput(messageTable: InputDiagnosticMessageTable, inputFilePathRel: string, thisFilePathRel: string): string {
-    let result =
-        "// <auto-generated />\r\n" +
-        "// generated from '" + inputFilePathRel + "' by '" + thisFilePathRel.replace(/\\/g, "/") + "'\r\n" +
-        "/* @internal */\r\n" +
-        "namespace ts {\r\n" +
-        "    function diag(code: number, category: DiagnosticCategory, key: string, message: string, reportsUnnecessary?: {}, elidedInCompatabilityPyramid?: boolean, reportsDeprecated?: {}): DiagnosticMessage {\r\n" +
-        "        return { code, category, key, message, reportsUnnecessary, elidedInCompatabilityPyramid, reportsDeprecated };\r\n" +
-        "    }\r\n" +
-        "    export const Diagnostics = {\r\n";
+function buildInfoFileOutput(messageTable: InputDiagnosticMessageTable, inputFilePathRel: string): string {
+    const result = [
+        "// <auto-generated />",
+        `// generated from '${inputFilePathRel}'`,
+        "",
+        "import { DiagnosticCategory, DiagnosticMessage } from \"./ts\";",
+        "",
+        "function diag(code: number, category: DiagnosticCategory, key: string, message: string, reportsUnnecessary?: {}, elidedInCompatabilityPyramid?: boolean, reportsDeprecated?: {}): DiagnosticMessage {",
+        "    return { code, category, key, message, reportsUnnecessary, elidedInCompatabilityPyramid, reportsDeprecated };",
+        "}",
+        "",
+        "export const Diagnostics = {",
+    ];
     messageTable.forEach(({ code, category, reportsUnnecessary, elidedInCompatabilityPyramid, reportsDeprecated }, name) => {
         const propName = convertPropertyName(name);
         const argReportsUnnecessary = reportsUnnecessary ? `, /*reportsUnnecessary*/ ${reportsUnnecessary}` : "";
         const argElidedInCompatabilityPyramid = elidedInCompatabilityPyramid ? `${!reportsUnnecessary ? ", /*reportsUnnecessary*/ undefined" : ""}, /*elidedInCompatabilityPyramid*/ ${elidedInCompatabilityPyramid}` : "";
         const argReportsDeprecated = reportsDeprecated ? `${!argElidedInCompatabilityPyramid ? ", /*reportsUnnecessary*/ undefined, /*elidedInCompatabilityPyramid*/ undefined" : ""}, /*reportsDeprecated*/ ${reportsDeprecated}` : "";
 
-        result += `        ${propName}: diag(${code}, DiagnosticCategory.${category}, "${createKey(propName, code)}", ${JSON.stringify(name)}${argReportsUnnecessary}${argElidedInCompatabilityPyramid}${argReportsDeprecated}),\r\n`;
+        result.push(`    ${propName}: diag(${code}, DiagnosticCategory.${category}, "${createKey(propName, code)}", ${JSON.stringify(name)}${argReportsUnnecessary}${argElidedInCompatabilityPyramid}${argReportsDeprecated}),`);
     });
 
-    result += "    };\r\n}";
+    result.push("};");
 
-    return result;
+    return result.join("\r\n");
 }
 
 function buildDiagnosticMessageOutput(messageTable: InputDiagnosticMessageTable): string {