Auto merge of #19730 - NLincoln:19172-number-input-type-validations, r=KiChjang

number input type validations

I used rust's builtin float parser to implement this. Rust's parser is more permissive than what browsers support (in this case), so I added some code to handle those edge cases.

This passes all the prewritten test cases locally, but I fell asleep last night before updating the manifests 😅

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes are part of #19172

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- [X] There are tests for these changes

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components/script/dom/bindings/str.rs

@@ -303,6 +303,16 @@ impl DOMString {
         parse_week_string(&*self.0).is_ok()
     }
 
+    /// A valid number is the same as what rust considers to be valid,
+    /// except for +1., NaN, and Infinity.
+    /// https://html.spec.whatwg.org/multipage/#valid-floating-point-number
+    pub fn is_valid_number_string(&self) -> bool {
+        let input = &self.0;
+        input.parse::<f64>().ok().map_or(false, |val| {
+            !(val.is_infinite() || val.is_nan() || input.ends_with(".") || input.starts_with("+"))
+        })
+    }
+
     /// A valid normalized local date and time string should be "{date}T{time}"
     /// where date and time are both valid, and the time string must be as short as possible
     /// https://html.spec.whatwg.org/multipage/#valid-normalised-local-date-and-time-string

components/script/dom/htmlinputelement.rs

@@ -1045,6 +1045,12 @@ impl HTMLInputElement {
                         textinput.single_line_content_mut().clear();
                 }
             }
+            InputType::Number => {
+                let mut textinput = self.textinput.borrow_mut();
+                if !textinput.single_line_content().is_valid_number_string() {
+                    textinput.single_line_content_mut().clear();
+                }
+            }
             // TODO: Implement more value sanitization algorithms for different types of inputs
             _ => ()
         }