Function make

packages/core/src/system-context/index.ts:135–173

(source: Source<A>)

/** Closes a typed source into a context that composes with differently typed sources. */
export function make<A>(source: Source<A>): SystemContext {
  const decode = Schema.decodeUnknownOption(source.codec)
  const encode = Schema.encodeSync(source.codec)
  const equivalent = Schema.toEquivalence(source.codec)
  return context([
    {
      key: source.key,
      load: source.load.pipe(
        Effect.map((value) => {
          if (isUnavailable(value)) return value
          const snapshot = (): SourceSnapshot => ({
            value: encode(value),
            ...(source.removed ? { removed: requireText(source.key, "removal", source.removed(value)) } : {}),
          })
          return {
            baseline: (): Rendered => ({
              text: requireText(source.key, "baseline", source.baseline(value)),
              snapshot: snapshot(),
            }),
            compare: (previous): Compared =>
              Option.match(decode(previous), {
                onNone: (): Compared => ({ _tag: "Incompatible" }),
                onSome: (decoded): Compared =>
                  equivalent(decoded, value)
                    ? { _tag: "Unchanged" }
                    : {
                        _tag: "Updated",
                        render: () => ({
                          text: requireText(source.key, "update", source.update(decoded, value)),
                          snapshot: snapshot(),
                        }),
                      },
              }),
          }
        }),
      ),
    },
  ])
}

/** Combines contexts in order and rejects duplicate source keys immediately. */
export function combine(values: ReadonlyArray<SystemContext>): SystemContext {