chore: add vendor dependencies for kauma build

vendor/serde_json/tests/lexical/exponent.rs

@@ -0,0 +1,36 @@
+// Adapted from https://github.com/Alexhuszagh/rust-lexical.
+
+use crate::lexical::exponent::*;
+
+#[test]
+fn scientific_exponent_test() {
+    // 0 digits in the integer
+    assert_eq!(scientific_exponent(0, 0, 5), -6);
+    assert_eq!(scientific_exponent(10, 0, 5), 4);
+    assert_eq!(scientific_exponent(-10, 0, 5), -16);
+
+    // >0 digits in the integer
+    assert_eq!(scientific_exponent(0, 1, 5), 0);
+    assert_eq!(scientific_exponent(0, 2, 5), 1);
+    assert_eq!(scientific_exponent(0, 2, 20), 1);
+    assert_eq!(scientific_exponent(10, 2, 20), 11);
+    assert_eq!(scientific_exponent(-10, 2, 20), -9);
+
+    // Underflow
+    assert_eq!(scientific_exponent(i32::MIN, 0, 0), i32::MIN);
+    assert_eq!(scientific_exponent(i32::MIN, 0, 5), i32::MIN);
+
+    // Overflow
+    assert_eq!(scientific_exponent(i32::MAX, 0, 0), i32::MAX - 1);
+    assert_eq!(scientific_exponent(i32::MAX, 5, 0), i32::MAX);
+}
+
+#[test]
+fn mantissa_exponent_test() {
+    assert_eq!(mantissa_exponent(10, 5, 0), 5);
+    assert_eq!(mantissa_exponent(0, 5, 0), -5);
+    assert_eq!(mantissa_exponent(i32::MAX, 5, 0), i32::MAX - 5);
+    assert_eq!(mantissa_exponent(i32::MAX, 0, 5), i32::MAX);
+    assert_eq!(mantissa_exponent(i32::MIN, 5, 0), i32::MIN);
+    assert_eq!(mantissa_exponent(i32::MIN, 0, 5), i32::MIN + 5);
+}