Function isMissingDataOnly

repos/effect/packages/effect/src/Config.ts:298–325

(issue: SchemaIssue.Issue)

        ? f(resolution.value).pipe(
          Effect.mapEager((value) => resolved(value, resolution.hasInput)),
          Effect.mapErrorEager((error) => evaluationFailure(error, resolution.hasInput))
        )
        : Effect.succeed(resolution))
  )
})

/**
 * Provides a fallback config when parsing fails with a `ConfigError`.
 *
 * **When to use**
 *
 * Use when you need to try an alternative config source after the primary one
 * fails.
 *
 * **Details**
 *
 * Unlike {@link withDefault}, this handles both semantic absence and **all**
 * `ConfigError`s. The fallback function receives the error and returns a new
 * `Config`.
 *
 * **Gotchas**
 *
 * Recovery preserves whether the primary config read provider input. When the
 * recovered config is composed with {@link all}, invalid input in the primary
 * branch still makes the enclosing group partially supplied, so an outer
 * {@link withDefault} or {@link option} does not replace the whole group.
 *
 * **Example** (Falling back to a literal)
 *
 * ```ts import.meta.vitest
 * import { Config, ConfigProvider, Effect } from "effect"