display-error-true-cell.qmd

---
title: test
format: html
_quarto:
  tests:
    html:
      ensureHtmlElementContents: 
        selectors: ['div.cell-output-error']
        matches: ['ValueError\: Display phase error for HTML']
        noMatches: []
---

With `error: true` in cell, this document should not error at rendering and Exception at IPython.display level should be shown in output. 

By default `nbconvert` does not throw exception for error thrown by IPython display, on purpose as document output is still valid as there are other representation. 

```{python}
# First cell - create an object with a buggy _repr_html_ method
class BuggyDisplay:
    def __init__(self):
        self.data = "This works fine"
    
    def _repr_html_(self):
        # This error happens during display, not execution
        raise ValueError("Display phase error for HTML!")

    def _repr_markdown_(self):
        # Markdown representation as fallback when HTML fails
        return "**Markdown fallback:** " + self.data

    def __repr__(self):
        # This ensures the object has a string representation
        return self.data

# Create the object
buggy = BuggyDisplay()
```

```{python}
#| error: true
buggy
```

```{python}
print("Execution continued despite display error")
```