Phantom Imports and Redundant Parameters
The examples in casehub-pages had been lying for a while. Forty-three TypeScript files importing from @casehubio/ui and @casehubio/data — packages that don’t exist. They were never compiled, never type-checked, and the functions they imported (inlineDataset, dataset, groupOp) had either been removed from exports or never existed as callable functions. The examples were documentation that documented the wrong API.
Phase 8 of the DataSource migration (#143) was supposed to be mechanical: swap inlineDataset() for bind() + inlineSource(), swap dataset() for bind() + restSource(). But tracing the imports back to their roots surfaced two design problems worth fixing first.
The first was restSource. Its signature was restSource(url, dataSetId, options?) — taking a dataset id that bind() already provides. I followed the dataSetId through the implementation: it went into buildDef() to construct an ExternalDataSetDef, which was passed to extractDataSet(). But extractDataSet accepts ExtractionDef, not ExternalDataSetDef — and ExtractionDef has no uuid field. The parameter was dead on arrival. Removed it, changed buildDef() to return ExtractionDef directly.
The same parameter exists in sseSource and wsSource, but there it’s not redundant — push sources use it as the subscription topic for subscribe/unsubscribe. Different concern, same name.
The second problem was the phantom imports themselves. @casehubio/ui and @casehubio/data were shorthand names that never resolved to real packages. The examples also used groupOp, sortOp, filterOp as functions — but these only exist as type interfaces. Meanwhile, pages-ui already exports a full DSL with lookup, groupBy, col, sortBy, filterBy that does exactly what the phantom functions were supposed to do.
The migration ended up touching 48 files. The examples now import from real packages (@casehubio/pages-ui, @casehubio/pages-data), use the real DSL, and the data flows through bind() into page() via the datasets option. Net result: 413 fewer lines, mostly from removing JSON.stringify wrappers and collapsing the old verbose lookup syntax.
The examples still aren’t type-checked. About half of them use a legacy page() calling convention — objects and arrays as positional arguments — that doesn’t match the current page(name, ...components, options?) signature. Making them type-correct requires restructuring those calls, which is Phase 11 cleanup work. Filed as #179.