1 files changed, 24 insertions, 18 deletions
diff --git a/u/process/argv.ts b/u/process/argv.ts
index dcdba85..dca5098 100644
--- a/u/process/argv.ts
+++ b/u/process/argv.ts
@@ -1,4 +1,4 @@
-import { Either, type Mapper, type IEither } from '@emprespresso/pengueno';
+import { Either, type Mapper, type IEither, Optional } from '@emprespresso/pengueno';
 
 export const isArgKey = <K extends string>(k: string): k is K => k.startsWith('--');
 
@@ -13,22 +13,27 @@ export const getArg = <K extends string, V>(
     argv: Array<string>,
     whenValue: ArgHandler<V>,
 ): IEither<Error, V> => {
-    const value =
-        argv
-            .filter((_argv) => isArgKey(_argv) && _argv.split('=')[0] === arg)
-            .map((_argv, i) => {
-                const next = _argv.includes('=') ? _argv.split('=')[1] : argv.at(i + 1);
-                if (next) {
-                    if (isArgKey(next)) return whenValue.unspecified;
-                    return whenValue.present(next);
-                }
-                return whenValue.unspecified;
-            })
-            .find((x) => x) ?? whenValue.absent;
-    if (value === undefined) {
-        return Either.left(new Error('no value specified for ' + arg));
+    const argIndex = Optional.from(argv.findIndex((_argv) => isArgKey(_argv) && _argv.split('=')[0] === arg)).filter(
+        (index) => index >= 0 && index < argv.length,
+    );
+    if (!argIndex.present()) {
+        return Optional.from(whenValue.absent)
+            .map((v) => Either.right<Error, V>(v))
+            .orSome(() =>
+                Either.left(
+                    new Error(`arg ${arg} is not present in arguments list and does not have an 'absent' value`),
+                ),
+            )
+            .get();
     }
-    return Either.right(value);
+
+    return argIndex
+        .flatMap((idx) =>
+            Optional.from(argv.at(idx)).map((_argv) => (_argv.includes('=') ? _argv.split('=')[1] : argv.at(idx + 1))),
+        )
+        .map((next) => (isArgKey(next) ? whenValue.unspecified : whenValue.present(next)))
+        .map((v) => Either.right<Error, V>(<V>v))
+        .get();
 };
 
 type MappedArgs<
@@ -55,10 +60,10 @@ export const argv = <
         return getArg(arg, argv, handler).mapRight((value) => [arg, value] as const);
     };
 
-    return args
+    const res = args
         .map(processArg)
         .reduce(
-            (acc: IEither<Error, Partial<Result>>, current: IEither<Error, readonly [Args[number], unknown]>) =>
+            (acc: IEither<Error, Partial<Result>>, current: IEither<Error, [Args[number], unknown]>) =>
                 acc.flatMap((accValue) =>
                     current.mapRight(([key, value]) => ({
                         ...accValue,
@@ -68,4 +73,5 @@ export const argv = <
             Either.right(<Partial<Result>>{}),
         )
         .mapRight((result) => <Result>result);
+    return res;
 };