From 6ca9a9e3b768e8e4bd29813d9f649da7845252a3 Mon Sep 17 00:00:00 2001
From: Ryan <rkingsbury@users.noreply.github.com>
Date: Mon, 16 Oct 2023 23:14:55 -0400
Subject: [PATCH] Solution: always sort components by amount

---
 CHANGELOG.md          |  5 +++++
 src/pyEQL/solution.py | 12 ++++--------
 src/pyEQL/utils.py    |  2 ++
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 65bb9d70..330b9f06 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- `Solution.components` is now automatically sorted in descending order of amount, for
+  consistency with `anions`, `cations`, and `neutrals`.
+
 ### Fixed
 
 - Bugfix in `as_dict` to make serialization via `dumpfn` possible. Previously, `Quantity`
diff --git a/src/pyEQL/solution.py b/src/pyEQL/solution.py
index d6b6de62..0501794d 100644
--- a/src/pyEQL/solution.py
+++ b/src/pyEQL/solution.py
@@ -495,8 +495,7 @@ def cations(self) -> dict[str, float]:
         Returns the subset of `components` {formula: moles} that are cations. The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") > 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") > 0}
 
     @property
     def anions(self) -> dict[str, float]:
@@ -504,8 +503,7 @@ def anions(self) -> dict[str, float]:
         Returns the subset of `components` {formula: moles} that are anions. The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") < 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") < 0}
 
     @property
     def neutrals(self) -> dict[str, float]:
@@ -513,8 +511,7 @@ def neutrals(self) -> dict[str, float]:
         Returns the subset of `components` {formula: moles} that are neutral (not charged). The returned dict is sorted by
         amount in descending order.
         """
-        d = {k: v for k, v in self.components.items() if self.get_property(k, "charge") == 0}
-        return dict(sorted(d.items(), key=lambda x: x[1], reverse=True))
+        return {k: v for k, v in self.components.items() if self.get_property(k, "charge") == 0}
 
     # TODO - need tests for viscosity
     @property
@@ -1113,8 +1110,7 @@ def get_components_by_element(self) -> dict[str, list]:
         d = {}
         # by sorting the components according to amount, we ensure that the species
         # are sorted in descending order of concentration in the resulting dict
-        components = dict(sorted(self.components.items(), key=lambda x: x[1], reverse=True))
-        for s in components:
+        for s in self.components:
             # determine the element and oxidation state
             elements = self.get_property(s, "elements")
 
diff --git a/src/pyEQL/utils.py b/src/pyEQL/utils.py
index 9b49a1c8..48bebb87 100644
--- a/src/pyEQL/utils.py
+++ b/src/pyEQL/utils.py
@@ -45,6 +45,8 @@ def __getitem__(self, key):
 
     def __setitem__(self, key, value):
         super().__setitem__(standardize_formula(key), value)
+        # sort contents anytime an item is set
+        self.data = dict(sorted(self.items(), key=lambda x: x[1], reverse=True))
 
     def __delitem__(self, key):
         super().__delitem__(standardize_formula(key))