proptest reveals that dsl breaks at invalid char boundaries

edn/Cargo.toml

@@ -13,3 +13,4 @@ default = []
 
 [dev-dependencies]
 tek_tui = { path = "../tui" }
+proptest = "^1.6.0"

edn/proptest-regressions/iter.txt

@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc bbb90b16e6106f17dbb5a4f57594f451360a2ea7e3e20c28adeb8babc98d39df # shrinks to source = "(𰀀"

edn/proptest-regressions/token.txt

@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc 5fb814b74ae035bdecb536817090cfb473f0a874e9acf9aaa136a4794cdb367f # shrinks to source = "", start = 10336420442936153584, length = 8110323630773398032

edn/src/iter.rs

@@ -108,3 +108,20 @@ pub const fn to_digit (c: char) -> Result<usize, ParseError> {
         _ => return Result::Err(Unexpected(c))
     })
 }
+#[cfg(test)] mod test_token_iter {
+    use proptest::prelude::*;
+    proptest! {
+        #[test] fn proptest_source_iter (
+            source in "\\PC*"
+        ) {
+            let mut iter = crate::SourceIter::new(&source);
+            let _ = iter.next();
+        }
+        #[test] fn proptest_token_iter (
+            source in "\\PC*"
+        ) {
+            let mut iter = crate::TokenIter::new(&source);
+            let _ = iter.next();
+        }
+    }
+}

edn/src/lib.rs

@@ -35,45 +35,6 @@ pub(crate) use std::fmt::{Debug, Display, Formatter, Result as FormatResult};
         }
     }
 }
-#[cfg(test)] #[test] fn test_token () -> Result<(), Box<dyn std::error::Error>> {
-    let source = ":f00";
-    let mut token = Token { source, start: 0, length: 1, value: Sym(":") };
-    token = token.grow_sym();
-    assert_eq!(token, Token { source, start: 0, length: 2, value: Sym(":f") }); 
-    token = token.grow_sym();
-    assert_eq!(token, Token { source, start: 0, length: 3, value: Sym(":f0") }); 
-    token = token.grow_sym();
-    assert_eq!(token, Token { source, start: 0, length: 4, value: Sym(":f00") }); 
-
-    let src = "";
-    assert_eq!(None, SourceIter(src).next());
-
-    let src = "  \n    \r   \t  ";
-    assert_eq!(None, SourceIter(src).next());
-
-    let src = "7";
-    assert_eq!(Num(7), SourceIter(src).next().unwrap().0.value);
-
-    let src = "     100         ";
-    assert_eq!(Num(100), SourceIter(src).next().unwrap().0.value);
-
-    let src = "     9a         ";
-    assert_eq!(Err(Unexpected('a')), SourceIter(src).next().unwrap().0.value);
-
-    let src = "     :123foo      ";
-    assert_eq!(Sym(":123foo"), SourceIter(src).next().unwrap().0.value);
-
-    let src = " \r\r\r\n\n\n@bar456\t\t\t\t\t\t";
-    assert_eq!(Sym("@bar456"), SourceIter(src).next().unwrap().0.value);
-
-    let src = "foo123";
-    assert_eq!(Key("foo123"), SourceIter(src).next().unwrap().0.value);
-
-    let src = "foo/bar";
-    assert_eq!(Key("foo/bar"), SourceIter(src).next().unwrap().0.value);
-
-    Ok(())
-}
 //#[cfg(test)] #[test] fn test_examples () -> Result<(), ParseError> {    
     //// Let's pretend to render some view.
     //let source = include_str!("../../tek/src/view_arranger.edn");

edn/src/token.rs

@@ -41,7 +41,7 @@ impl<'a> Token<'a> {
         Self { source, start, length, value }
     }
     pub const fn end (&self) -> usize {
-        self.start + self.length
+        self.start.saturating_add(self.length)
     }
     pub const fn slice (&'a self) -> &'a str {
         self.slice_source(self.source)
@@ -51,7 +51,7 @@ impl<'a> Token<'a> {
         str_range(source, self.start, self.end())
     }
     pub const fn slice_source_exp <'b> (&'a self, source: &'b str) -> &'b str {
-        str_range(source, self.start + 1, self.end())
+        str_range(source, self.start.saturating_add(1), self.end())
     }
     pub const fn value (&self) -> Value {
         self.value
@@ -60,7 +60,7 @@ impl<'a> Token<'a> {
         Self { value: Value::Err(error), ..self }
     }
     pub const fn grow (self) -> Self {
-        Self { length: self.length + 1, ..self }
+        Self { length: self.length.saturating_add(1), ..self }
     }
     pub const fn grow_num (self, m: usize, c: char) -> Self {
         match to_digit(c) {
@@ -90,7 +90,7 @@ impl<'a> Token<'a> {
     pub const fn grow_in (self) -> Self {
         let mut token = self.grow_exp();
         if let Value::Exp(depth, source) = token.value {
-            token.value = Value::Exp(depth + 1, source)
+            token.value = Value::Exp(depth.saturating_add(1), source)
         } else {
             unreachable!()
         }
@@ -110,3 +110,60 @@ impl<'a> Token<'a> {
         token
     }
 }
+#[cfg(test)] mod test_token_prop {
+    use proptest::prelude::*;
+    proptest! {
+        #[test] fn test_token_prop (
+            source in "\\PC*",
+            start  in usize::MIN..usize::MAX,
+            length in usize::MIN..usize::MAX,
+        ) {
+            let token = crate::Token {
+                source: &source,
+                start,
+                length,
+                value: crate::Value::Nil
+            };
+            let _ = token.slice();
+        }
+    }
+}
+#[cfg(test)] #[test] fn test_token () -> Result<(), Box<dyn std::error::Error>> {
+    let source = ":f00";
+    let mut token = Token { source, start: 0, length: 1, value: Sym(":") };
+    token = token.grow_sym();
+    assert_eq!(token, Token { source, start: 0, length: 2, value: Sym(":f") }); 
+    token = token.grow_sym();
+    assert_eq!(token, Token { source, start: 0, length: 3, value: Sym(":f0") }); 
+    token = token.grow_sym();
+    assert_eq!(token, Token { source, start: 0, length: 4, value: Sym(":f00") }); 
+
+    let src = "";
+    assert_eq!(None, SourceIter(src).next());
+
+    let src = "  \n    \r   \t  ";
+    assert_eq!(None, SourceIter(src).next());
+
+    let src = "7";
+    assert_eq!(Num(7), SourceIter(src).next().unwrap().0.value);
+
+    let src = "     100         ";
+    assert_eq!(Num(100), SourceIter(src).next().unwrap().0.value);
+
+    let src = "     9a         ";
+    assert_eq!(Err(Unexpected('a')), SourceIter(src).next().unwrap().0.value);
+
+    let src = "     :123foo      ";
+    assert_eq!(Sym(":123foo"), SourceIter(src).next().unwrap().0.value);
+
+    let src = " \r\r\r\n\n\n@bar456\t\t\t\t\t\t";
+    assert_eq!(Sym("@bar456"), SourceIter(src).next().unwrap().0.value);
+
+    let src = "foo123";
+    assert_eq!(Key("foo123"), SourceIter(src).next().unwrap().0.value);
+
+    let src = "foo/bar";
+    assert_eq!(Key("foo/bar"), SourceIter(src).next().unwrap().0.value);
+
+    Ok(())
+}