Add support for LOG_LEVEL env var in pkl-gen-typescript (#42)

* Add support for LOG_LEVEL env var in pkl-gen-typescript

* remove unused import

pkl-gen-typescript/main.ts

@@ -1,6 +1,6 @@
 import chalk from "chalk";
 import { boolean, command, flag, option, optional, restPositionals, run, string } from "cmd-ts";
-import consola from "consola";
+import consola, { LogLevels } from "consola";
 import { access } from "fs/promises";
 import { join } from "path";
 import { cwd } from "process";
@@ -44,9 +44,24 @@ export const cli = command({
     }),
   },
   handler: async ({ pklModules, settingsFilePath, outputDirectory, dryRun, verbose }) => {
-    consola.level = verbose
-      ? 4
-      : (parseInt(process.env.CONSOLA_LEVEL ?? "") || null) ?? (process.env.DEBUG ? 4 : 3);
+    /*
+      Four ways to set the log level, in order of precedence:
+      - CLI flag "-v", sets log level to "debug"
+      - environment variable CONSOLA_LEVEL set to an integer
+      - environment variable LOG_LEVEL set to a string that is a valid log level name
+      - environment variable DEBUG, sets log level to "debug"
+      - defaults to "info"
+    */
+    const logLevel = verbose
+      ? LogLevels.debug
+      : (parseInt(process.env.CONSOLA_LEVEL ?? "") || null) ??
+          (process.env.LOG_LEVEL !== undefined &&
+            Object.keys(LogLevels).includes(process.env.LOG_LEVEL.toLowerCase()))
+        ? LogLevels[process.env.LOG_LEVEL?.toLowerCase() as keyof typeof LogLevels]
+        : process.env.DEBUG
+          ? LogLevels.debug
+          : LogLevels.info;
+    consola.level = logLevel;
 
     if (!pklModules.length) {
       consola.error("You must provide at least one file to evaluate.");