Bootstrap v4 to v6 Migration

There is no direct v4 to v6 path. Migrate in two stages — v4 to v5 first (this skill), then v5 to v6 (the bootstrap-v5-v6-migration skill). Skipping the middle stage doesn't work, because many v4 names were renamed in v5 and renamed again in v6: .text-primary becomes .fg-primary only after passing through v5, and .badge-primary becomes .badge.theme-primary by way of .badge.bg-primary.

Workflow

Work through each step in order. After each step, search the codebase for remaining v4 patterns before moving on.

• Step 1: Plan the two-stage migration
• Step 2: v4 to v5 — dependencies, build, and Sass
• Step 3: v4 to v5 — JavaScript
• Step 4: v4 to v5 — classes and attributes
• Step 5: v5 to v6 — hand off to the v6 migration skill
• Step 6: Verify

Step 1: Plan the two-stage migration