feat(FR-1681): implement automatic shared memory calculation in session creation

[yomybaby]

Resolves (FR-1681)

Summary

Implement automatic shared memory (shmem) calculation in the startSessionWithDefault function to ensure consistency with UI-based session creation.

Changes

• Added automatic shmem calculation logic in useStartSession.tsx
• When enabledAutomaticShmem is enabled and memory is allocated:
  • If memory ≥ 4GB → shmem = 1GB
  • If memory < 4GB → shmem = 64MB (default)
• Imports AUTOMATIC_DEFAULT_SHMEM constant and compareNumberWithUnits helper

Background

Previously, the ResourceAllocationFormItems component had automatic shmem calculation logic, but programmatic session creation through useStartSession hook did not apply the same logic. This created inconsistency between UI-based and programmatic session creation, potentially leading to suboptimal resource allocation.

Test Plan

• Verify shmem is automatically set to 1GB when memory ≥ 4GB
• Verify shmem is automatically set to 64MB when memory < 4GB
• Confirm consistency with ResourceAllocationFormItems behavior

[yomybaby]

• feat(FR-1681): implement automatic shared memory calculation in session creation #4644 👈 (View in Graphite)
• main

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[github-actions]

Coverage report for ./react

St.❔	Category	Percentage	Covered / Total
🔴	Statements	4.69% (+0% 🔼)	547/11669
🔴	Branches	3.82% (+0% 🔼)	314/8221
🔴	Functions	2.91% (-0% 🔻)	104/3577
🔴	Lines	4.64% (+0% 🔼)	529/11410

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Test suite run success

125 tests passing in 14 suites.

Report generated by 🧪jest coverage report action from a627ebb

[Copilot]

Pull Request Overview

This PR implements automatic shared memory (shmem) calculation in the startSessionWithDefault function to ensure consistency with UI-based session creation.

Key Changes:

• Added automatic shmem calculation logic that sets shmem to 1GB when memory ≥ 4GB, otherwise 64MB
• Imports AUTOMATIC_DEFAULT_SHMEM constant and compareNumberWithUnits helper function
• Logic is applied when enabledAutomaticShmem flag is enabled and memory is allocated

[Copilot]

The automatic shmem calculation logic is inconsistent with the original implementation in ResourceAllocationFormItems.tsx.

Issues:

1. The runShmemAutomationRule function in ResourceAllocationFormItems.tsx expects M_plus_S (Memory + Shared Memory combined), but this implementation only uses mem (Memory alone)
2. Missing validation: The original logic checks if M+S > M+1G to ensure there's enough memory to allocate 1GB for shmem
3. Missing check: The original verifies compareNumberWithUnits('1g', AUTOMATIC_DEFAULT_SHMEM) > 0 to avoid downgrading shmem

Recommended fix:

// Apply automatic shmem calculation if enabledAutomaticShmem is true
if (mergedValue.enabledAutomaticShmem && mergedValue.resource?.mem) {
  const mem = mergedValue.resource.mem;
  const currentShmem = mergedValue.resource.shmem || AUTOMATIC_DEFAULT_SHMEM;
  const M_plus_S = addNumberWithUnits(mem, currentShmem, 'g') || '0g';

  // Apply the same logic as ResourceAllocationFormItems
  if (
    compareNumberWithUnits(M_plus_S, '4g') >= 0 &&
    compareNumberWithUnits(M_plus_S, addNumberWithUnits(mem, '1g') || '0b') >= 0 &&
    compareNumberWithUnits('1g', AUTOMATIC_DEFAULT_SHMEM) > 0
  ) {
    mergedValue.resource.shmem = '1g';
  } else {
    mergedValue.resource.shmem = AUTOMATIC_DEFAULT_SHMEM;
  }
}

Note: You'll also need to import addNumberWithUnits from the helper module.

[agatha197]

please check copilot's reviews.