Fixed command id collision. Added class support in style preset

tests/core/formatting/test_engine.py

@@ -8,6 +8,7 @@ from myfasthtml.core.formatting.dataclasses import (
     FormatRule,
 )
 from myfasthtml.core.formatting.engine import FormattingEngine
+from myfasthtml.core.formatting.style_resolver import StyleContainer
 
 
 class TestApplyFormat:
@@ -18,9 +19,9 @@ class TestApplyFormat:
 
         css, formatted = engine.apply_format(rules, cell_value=42)
 
-        assert css is not None
-        assert "background-color: red" in css
-        assert "color: white" in css
+        assert isinstance(css, StyleContainer)
+        assert "background-color: red" in css.css
+        assert "color: white" in css.css
         assert formatted is None
 
     def test_apply_format_with_formatter_only(self):
@@ -45,8 +46,8 @@ class TestApplyFormat:
 
         css, formatted = engine.apply_format(rules, cell_value=42.567)
 
-        assert css is not None
-        assert "color: green" in css
+        assert isinstance(css, StyleContainer)
+        assert "color: green" in css.css
         assert formatted == "42.57"
 
     def test_apply_format_condition_met(self):
@@ -61,8 +62,8 @@ class TestApplyFormat:
 
         css, formatted = engine.apply_format(rules, cell_value=-5)
 
-        assert css is not None
-        assert "color: red" in css
+        assert isinstance(css, StyleContainer)
+        assert "color: red" in css.css
 
     def test_apply_format_condition_not_met(self):
         """Conditional rule does not apply when condition is not met."""
@@ -97,8 +98,8 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value="anything")
 
-        assert css is not None
-        assert "color: gray" in css
+        assert isinstance(css, StyleContainer)
+        assert "color: gray" in css.css
 
     def test_multiple_unconditional_rules_last_wins(self):
         """Among unconditional rules, last one wins."""
@@ -111,9 +112,9 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=42)
 
-        assert "color: green" in css
-        assert "color: red" not in css
-        assert "color: blue" not in css
+        assert "color: green" in css.css
+        assert "color: red" not in css.css
+        assert "color: blue" not in css.css
 
     def test_conditional_beats_unconditional(self):
         """Conditional rule (higher specificity) beats unconditional."""
@@ -128,8 +129,8 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=-5)
 
-        assert "color: red" in css
-        assert "color: gray" not in css
+        assert "color: red" in css.css
+        assert "color: gray" not in css.css
 
     def test_conditional_not_met_falls_back_to_unconditional(self):
         """When conditional doesn't match, unconditional applies."""
@@ -144,7 +145,7 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=5)  # positive, condition not met
 
-        assert "color: gray" in css
+        assert "color: gray" in css.css
 
     def test_multiple_conditional_last_wins(self):
         """Among conditional rules with same specificity, last wins."""
@@ -162,8 +163,8 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=5)
 
-        assert "color: blue" in css
-        assert "color: red" not in css
+        assert "color: blue" in css.css
+        assert "color: red" not in css.css
 
     def test_spec_example_value_minus_5(self):
         """
@@ -190,7 +191,7 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=-5)
 
-        assert "color: black" in css
+        assert "color: black" in css.css
 
     def test_spec_example_value_minus_3(self):
         """
@@ -213,7 +214,7 @@ class TestConflictResolution:
 
         css, _ = engine.apply_format(rules, cell_value=-3)
 
-        assert "color: red" in css
+        assert "color: red" in css.css
 
     def test_style_and_formatter_fusion(self):
         """
@@ -241,8 +242,8 @@ class TestConflictResolution:
         # Case 1: Condition met (value > budget)
         css, formatted = engine.apply_format(rules, cell_value=150, row_data=row_data)
 
-        assert css is not None
-        assert "var(--color-secondary)" in css  # Style from Rule 2
+        assert isinstance(css, StyleContainer)
+        assert "var(--color-secondary)" in css.css  # Style from Rule 2
         assert formatted == "150.00 €"  # Formatter from Rule 1
 
         # Case 2: Condition not met (value <= budget)
@@ -281,7 +282,7 @@ class TestConflictResolution:
 
         css, formatted = engine.apply_format(rules, cell_value=-5.67)
 
-        assert "var(--color-error)" in css  # Rule 3 wins for style
+        assert "var(--color-error)" in css.css  # Rule 3 wins for style
         assert formatted == "-6 €"  # Rule 4 wins for formatter (precision=0)
 
 
@@ -299,7 +300,7 @@ class TestWithRowData:
 
         css, _ = engine.apply_format(rules, cell_value=150, row_data=row_data)
 
-        assert "color: red" in css
+        assert "color: red" in css.css
 
     def test_condition_with_col_parameter(self):
         """Row-level condition using col parameter."""
@@ -314,8 +315,8 @@ class TestWithRowData:
 
         css, _ = engine.apply_format(rules, cell_value=42, row_data=row_data)
 
-        assert css is not None
-        assert "background-color" in css
+        assert isinstance(css, StyleContainer)
+        assert "background-color" in css.css
 
 
 class TestPresets:
@@ -326,7 +327,7 @@ class TestPresets:
 
         css, _ = engine.apply_format(rules, cell_value=42)
 
-        assert "var(--color-success)" in css
+        assert "var(--color-success)" in css.css
 
     def test_formatter_preset(self):
         """Formatter preset is resolved correctly."""
@@ -347,5 +348,5 @@ class TestPresets:
 
         css, _ = engine.apply_format(rules, cell_value=42)
 
-        assert "background-color: purple" in css
-        assert "color: yellow" in css
+        assert "background-color: purple" in css.css
+        assert "color: yellow" in css.css