From fe79d63c004f75e79764aa0ef640365b4cd3c3e9 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Wed, 29 Dec 2021 11:47:26 -0600
Subject: [PATCH] fix(error): Improve dotted key overwrite error

Fixes #252
---
 src/parser/errors.rs                                | 12 ++++++++++++
 src/parser/inline_table.rs                          |  6 +++---
 src/parser/table.rs                                 | 12 ++++++++++--
 tests/fixtures/invalid/duplicate-keys-dotted.stderr |  6 ++++++
 tests/fixtures/invalid/duplicate-keys-dotted.toml   |  4 ++++
 5 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 tests/fixtures/invalid/duplicate-keys-dotted.stderr
 create mode 100644 tests/fixtures/invalid/duplicate-keys-dotted.toml

diff --git a/src/parser/errors.rs b/src/parser/errors.rs
index 3539ba27..295d3c5b 100644
--- a/src/parser/errors.rs
+++ b/src/parser/errors.rs
@@ -239,6 +239,10 @@ pub(crate) enum CustomError {
         key: String,
         table: Option<Vec<Key>>,
     },
+    DottedKeyExtendWrongType {
+        key: Vec<Key>,
+        actual: &'static str,
+    },
     InvalidHexEscape(u32),
     UnparsedLine,
     OutOfRange,
@@ -265,6 +269,14 @@ impl Display for CustomError {
                     writeln!(f, "Duplicate key `{}`", key)
                 }
             }
+            CustomError::DottedKeyExtendWrongType { key, actual } => {
+                let path = key.iter().join(".");
+                writeln!(
+                    f,
+                    "Dotted key `{}` attempted to extend non-table type (`{}`)",
+                    path, actual
+                )
+            }
             CustomError::InvalidHexEscape(h) => {
                 writeln!(f, "Invalid hex escape code: {:x} ", h)
             }
diff --git a/src/parser/inline_table.rs b/src/parser/inline_table.rs
index c51737c6..7cc9d43a 100644
--- a/src/parser/inline_table.rs
+++ b/src/parser/inline_table.rs
@@ -1,7 +1,7 @@
 use crate::key::Key;
 use crate::parser::errors::CustomError;
 use crate::parser::key::key;
-use crate::parser::table::duplicate_key;
+use crate::parser::table::extend_wrong_type;
 use crate::parser::trivia::ws;
 use crate::parser::value::value;
 use crate::table::TableKeyValue;
@@ -57,8 +57,8 @@ fn descend_path<'a>(
             Value::InlineTable(ref mut sweet_child_of_mine) => {
                 table = sweet_child_of_mine;
             }
-            _ => {
-                return Err(duplicate_key(path, i));
+            ref v => {
+                return Err(extend_wrong_type(path, i, v.type_name()));
             }
         }
     }
diff --git a/src/parser/table.rs b/src/parser/table.rs
index f73c4c6e..6c17df75 100644
--- a/src/parser/table.rs
+++ b/src/parser/table.rs
@@ -76,6 +76,14 @@ pub(crate) fn duplicate_key(path: &[Key], i: usize) -> CustomError {
     }
 }
 
+pub(crate) fn extend_wrong_type(path: &[Key], i: usize, actual: &'static str) -> CustomError {
+    assert!(i < path.len());
+    CustomError::DottedKeyExtendWrongType {
+        key: path[..=i].to_vec(),
+        actual,
+    }
+}
+
 impl TomlParser {
     pub(crate) fn descend_path<'t, 'k>(
         mut table: &'t mut Table,
@@ -91,8 +99,8 @@ impl TomlParser {
                 Item::Table(new_table)
             });
             match *entry {
-                Item::Value(..) => {
-                    return Err(duplicate_key(path, i));
+                Item::Value(ref v) => {
+                    return Err(extend_wrong_type(path, i, v.type_name()));
                 }
                 Item::ArrayOfTables(ref mut array) => {
                     debug_assert!(!array.is_empty());
diff --git a/tests/fixtures/invalid/duplicate-keys-dotted.stderr b/tests/fixtures/invalid/duplicate-keys-dotted.stderr
new file mode 100644
index 00000000..c6d08ac6
--- /dev/null
+++ b/tests/fixtures/invalid/duplicate-keys-dotted.stderr
@@ -0,0 +1,6 @@
+TOML parse error at line 3, column 1
+  |
+3 | ssl-version.min = 'tlsv1.2'
+  | ^
+Dotted key `ssl-version` attempted to extend non-table type (`string`)
+
diff --git a/tests/fixtures/invalid/duplicate-keys-dotted.toml b/tests/fixtures/invalid/duplicate-keys-dotted.toml
new file mode 100644
index 00000000..199f36e7
--- /dev/null
+++ b/tests/fixtures/invalid/duplicate-keys-dotted.toml
@@ -0,0 +1,4 @@
+[http]
+ssl-version = 'tlsv1.1'
+ssl-version.min = 'tlsv1.2'
+ssl-version.max = 'tlsv1.3'