Add assertEqual function to KCL stdlib (#3279)

Takes a tolerance, because floating-point imprecision.

docs/kcl/index.md

@@ -21,6 +21,7 @@ layout: manual
 * [`arc`](kcl/arc)
 * [`asin`](kcl/asin)
 * [`assert`](kcl/assert)
+* [`assertEqual`](kcl/assertEqual)
 * [`assertGreaterThan`](kcl/assertGreaterThan)
 * [`assertGreaterThanOrEq`](kcl/assertGreaterThanOrEq)
 * [`assertLessThan`](kcl/assertLessThan)

docs/kcl/std.json

@@ -54791,6 +54791,62 @@
       "const myVar = true\nassert(myVar, \"should always be true\")"
     ]
   },
+  {
+    "name": "assertEqual",
+    "summary": "Check that a numerical value equals another at runtime,",
+    "description": "otherwise raise an error.",
+    "tags": [],
+    "args": [
+      {
+        "name": "left",
+        "type": "number",
+        "schema": {
+          "type": "number",
+          "format": "double"
+        },
+        "required": true
+      },
+      {
+        "name": "right",
+        "type": "number",
+        "schema": {
+          "type": "number",
+          "format": "double"
+        },
+        "required": true
+      },
+      {
+        "name": "epsilon",
+        "type": "number",
+        "schema": {
+          "type": "number",
+          "format": "double"
+        },
+        "required": true
+      },
+      {
+        "name": "message",
+        "type": "string",
+        "schema": {
+          "type": "string"
+        },
+        "required": true
+      }
+    ],
+    "returnValue": {
+      "name": "",
+      "type": "()",
+      "schema": {
+        "type": "null"
+      },
+      "required": true
+    },
+    "unpublished": false,
+    "deprecated": false,
+    "examples": [
+      "let n = 1.0285\nlet m = 1.0286\nassertEqual(n, m, 0.01, \"n is within the given tolerance for m\")"
+    ]
+  },
   {
     "name": "assertGreaterThan",
     "summary": "Check that a numerical value is greater than another at runtime,",