EPBDS-16211 E5: retire propTypes and the prop-types package - #145

What changes

E5: every propTypes declaration is gone, and so is prop-types. rg "prop-types" src returns nothing. The package is out of devDependencies, and lint rejects an import of it.

What is deleted

• 39 propTypes blocks in 38 files. The E2 and E3 conversions kept each block on purpose, so this is one deletion rather than forty.
• The semantic proxy components/types.ts, the barrel's PropTypes re-export, and every prop-types and type import.
• The host's and the form layer's handling of prop types. documentHost.ts copied the class's prop types onto the function component, and withFormSetup merged them under its own. The four tests that pinned both now pin the rest of what they covered.

The descriptions survive, in the props types

• They moved into the props types' JSDoc first, wherever a type did not carry them yet: TableView, Tabs, Upload, ProgressSteps, AutoSave, asField, asInputDateField and ToggleField.
• UIRender's three undocumented props are documented in the published UIRender.UIRenderProps, where a host reads them: initialValues, form and embedded. The form layer's props are described in a comment where the layer reads them.
• A script compared every commented prop with its TS declaration. What it still lists is documented by a type alias or by the published type.
• Comments that cited propTypes as a fact are reworded: Counter, Listbox, StandaloneTabs, documentHost and the form layer.

Not done, deliberately: the vocabulary as TS aliases

The plan's E5 step 2 asked for the type proxy to be recreated as aliases, such as type Id = string and type Px = number. I measured first:

• The proxy defined 41 names, and the converted files used 16.
• Twelve of the 16 restate PropTypes itself: type.String, type.Method, type.Of, and so on.
• Four carry a meaning of their own: Id (used twice), Fraction, UrlOrBase64OrPreview and NumberOrString.
• E2 and E3 already wrote that meaning into the props' JSDoc, for example "Fraction from 0 to 1" and "URL to link to".

An alias of a primitive checks nothing. The vocabulary would have been the same documentation in a second place, and 25 of its names would never have been used. The plan records this decision.

No diagnostic a test relied on is lost

• React 16 to 18 warn in development on a failed prop type. React 19 checks none.
• Two suites allowed prop-type warnings: four entries in the examples suite, and two in the nested-row suite.
• None of the six fired. I measured this on React 18, on master, just before the deletion. They are removed, and the nested-row suite now requires no warning at all.
• The formProps/instance warnings that the plan's §8 flagged were not taken as the contract being met. The declaration itself was wrong. A nested Data document shares its parent's form and is rendered without either prop. EPBDS-16211: fix the bugs the modernization found, and the docs that drifted #139 made both optional.

Kept from coming back

• prop-types is still installed, as a dependency of eslint-plugin-react, react-markdown and the React 16 fixture. An import would therefore resolve and bundle it again.
• no-restricted-imports now rejects it in all seven src overrides. I proved this with a probe file in core, in a test and in the demo; each failed with the rule's message.
• CLAUDE.md states the rule: no propTypes block. A component's props type, and its JSDoc, are the documentation.

Also

• README.md no longer lists prop-types among the bundled libraries.
• docs/SUPPORTED-PROPS.md is regenerated. Only Dropdown.tsx's line count changed, from 381 to 364.
• The wrong colGroup propType that E3 recorded ({styles}) is gone with the rest. The TS type says style.
• docs/UPGRADE-PLAN.md records E5 and closes its items: the §2 audit line, the §8 row, the E-checks row and the Appendix C checklist. The Appendix C command now looks for a dependency entry, since the lint rule names the package seven times.

Found, and left for a change of its own

On React 18, the examples suite's other five allowlist entries match nothing either. Whether any of them still guards something on 16, 17 or 19 is for that change to measure.

Measured

Both bundles were built from git archive copies in the same directory. Built in the worktree, the same trees measure 322,919 and 311,529 bytes; 322,919 is the figure #144 recorded.

Gates

All exited 0, run on this branch:

• lint:js, lint:css, typecheck, typecheck:contract;
• docs:props:check, docs:views:check, css:fixture:check;
• test:env-flags, build;
• test:coverage, thresholds included;
• test:pack, test:pack:peers, test:types;
• test:react16, test:react17, test:react19, 2842 tests each, with no worker crash;
• test:e2e, 41 tests;
• the manifest contract.

The suite still has 2842 tests. Four tests, in three suites, pinned prop-type forwarding and merging. Each now pins the rest of its subject: the names, the class left as written, and the state shape.

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