Process hangs indefinitely when using lineHeight property in specific layout contexts

[tomer-amir-pan]

Bug Report

Description

The PDF rendering process hangs indefinitely (infinite loop) when using the lineHeight property on a Text component within a flex container.

Environment

• @react-pdf/renderer version: 4.3.1
• Node.js version: v20.19.5
• Operating System: macOS

Reproduction

The following code causes the renderer to hang during PDF generation:

const styles = StyleSheet.create({
    metricValueContainer: {
        flexDirection: 'row',
        alignItems: 'center',
    },
    metricValue: {
        fontSize: 19.2,
        color: '#333333',
        lineHeight: 25.6,  // This causes the hang
    },
})

// Usage in component
<View style={styles.metricValueContainer}>
    <Text style={styles.metricValue}>
        {value}
    </Text>
</View>

Expected Behavior

The PDF should render successfully with the specified line height.

Actual Behavior

The process hangs indefinitely during PDF generation. No error is thrown, the process just never completes.

Workaround

Removing or commenting out the lineHeight property resolves the issue:

metricValue: {
    fontSize: 19.2,
    color: '#333333',
    // lineHeight: 25.6,  // Removed to prevent hang
},

Additional Context

• The hang appears to be related to layout calculations in the yoga-layout engine
• The specific ratio between fontSize and lineHeight seems to trigger the issue
• Other lineHeight values in the same file (e.g., lineHeight: 8.889) work fine
• The issue occurs specifically when the Text is inside a flex container with alignItems: 'center'

Possible Related Issues

This might be related to infinite layout recalculation loops when the layout engine tries to calculate text bounds with certain lineHeight values in flex contexts.

Would appreciate any insights or fixes for this issue!

[tomer-amir-pan]

Update

After further investigation, I need to correct my initial report. While commenting out the lineHeight property appeared to resolve the hang initially, I cannot confirm that lineHeight itself was the root cause.

The hang may have been caused by other factors or a combination of properties. I'm leaving this issue open in case others have experienced similar hangs with lineHeight, but wanted to note that the exact cause is still unclear.

Apologies for the confusion.