From c4c1c6c54d0670ca9bb02b1f324c935564f7eea3 Mon Sep 17 00:00:00 2001
From: Mark Ford <mark@massfords.com>
Date: Tue, 24 Dec 2024 10:34:37 -0500
Subject: [PATCH] improve validation of MathAdd (#25)

* fix: update the grammar for the math add intrinsic func args
* fix: support negative numbers as literal values
---
 package.json                       |  2 +-
 src/__tests__/validatePath.test.ts | 32 ++++++++++++++++++++++++++++++
 src/aslPaths.pegjs                 |  7 +++++--
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 8c0fdda..1a6bcf5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "asl-path-validator",
-  "version": "0.15.0",
+  "version": "0.16.0",
   "description": "Validates the path expressions for the Amazon States Language",
   "main": "./dist/index.js",
   "scripts": {
diff --git a/src/__tests__/validatePath.test.ts b/src/__tests__/validatePath.test.ts
index 5fda749..c2b4545 100644
--- a/src/__tests__/validatePath.test.ts
+++ b/src/__tests__/validatePath.test.ts
@@ -132,6 +132,38 @@ describe("unit tests for the parser", () => {
       path: "States.MathAdd($.value1, $.step)",
       valid_in: PayloadTemplatesOnly,
     },
+    {
+      path: "States.MathAdd($.value1, -1)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd($.value1, 1)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd(1, -1)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd(-1, -1)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd(1, $.step)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd(-1, $.step)",
+      valid_in: PayloadTemplatesOnly,
+    },
+    {
+      path: "States.MathAdd('-1', 'abc')",
+      valid_in: None,
+    },
+    {
+      path: "States.MathAdd(States.ArrayLength($$.Execution.Input.machines),-1)",
+      valid_in: PayloadTemplatesOnly,
+    },
     {
       path: "States.StringSplit($.inputString, $.splitter)",
       valid_in: PayloadTemplatesOnly,
diff --git a/src/aslPaths.pegjs b/src/aslPaths.pegjs
index 296c9ee..5ce7094 100644
--- a/src/aslPaths.pegjs
+++ b/src/aslPaths.pegjs
@@ -63,7 +63,10 @@ intrinsic_function
     / func:"States.StringToJson" args:single_arg {return {func, args}}
     / func:"States.JsonToString" args:single_arg {return {func, args}}
     / func:"States.MathRandom" args:function_args {return {func, args}}
-    / func:"States.MathAdd" args:function_args {return {func, args}}
+    / func:"States.MathAdd" PAREN_LEFT _ arg1:jsonpath_ _ COMMA _ arg2:jsonpath_ _ PAREN_RIGHT {return {func, arg1, arg2}}
+    / func:"States.MathAdd" PAREN_LEFT _ arg1:jsonpath_ _ COMMA _ arg2:(MINUS? NUMBER) _ PAREN_RIGHT {return {func, arg1, arg2}}
+    / func:"States.MathAdd" PAREN_LEFT _ arg1:(MINUS? NUMBER) _ COMMA _ arg2:jsonpath_ _ PAREN_RIGHT {return {func, arg1, arg2}}
+    / func:"States.MathAdd" PAREN_LEFT _ arg1:(MINUS? NUMBER) _ COMMA _ arg2:(MINUS? NUMBER) _ PAREN_RIGHT {return {func, arg1, arg2}}
     / func:"States.StringSplit" args:function_args {return {func, args}}
     / func:"States.UUID" args:no_args {return {func, args}}
 	/ func:"States.Format" args:function_args {return {func, args}}
@@ -119,7 +122,7 @@ comparison_op
 
 value
    = STRING
-   / NUMBER
+   / minus:MINUS? nbr:NUMBER { return (minus === '-' ? -1 : 1) * parseFloat(nbr)}
    / TRUE
    / FALSE
    / NULL