Single-layer property replacement is inappropriate for ES modules #262

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1. searls

   added

   enhancement

   on Jun 14, 2017
2. searls

   added a commit that references this issue on Jun 14, 2017

   This is blocked by #262 b/c I can't fake log

   62ff2be
3. searls commented on Jun 18, 2017

   

   searls

   on Jun 18, 2017

   MemberAuthor

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   Here's some pseudocode for what I'm thinking. This'll be a new freshly-driven src/imitate module which will recursively iterate properties of an original item and copy and/or fake them to a target, while also doing something to break cycles.

   If we do it right, it will:

   • actually detect cycles and fast-return any previously encountered objects (tricky because you might be looking at an imitation of a thing so we need a way to track them back to the original
   • not inadvertently overwrite deeply-nested properties in such a way that they are affected on the original (e.g. be careful about reaching deep into a shallow clone and monkeying around
   • allow us to rid all references to the td.replace throws with objects created with Object.create #257 modules gatherProps, copyProps and filterFunctions from all call sites in the "legacy" codebase, effectively getting td.func/td.object/td.constructor out of the business of imitating props at all.
   • give us a better sense of what the actual difference is between td.func and td.constructor, since the recursive algo will of course hit any function's prototype and iterate that too, making the distinction as we've expressed it up to now almost totally moot (for instance: why aren't constructor functions themselves test doubles in that case? must they actually be POJSF's wrapped with another fake? I'm starting to doubt it

   Psuedocomments

   export default (original, target, encounteredObjects = []) => {
     // 1. function, object, and constructor all immediately bail out to imitiate after creating their top-level thing (func, empty obj, func, respectively)
     // 2. guard: return original if not isObjectLike or isFunction
     // 2a. guard: return original if already encounteredObjects includes it
     // 3. gather all props on original
     // 4. copy all props to target
     // 5. for each prop:
     //   - if isConstructor, call constructor()
     //   - else if function call function()
     //   - else empty {}
     //   - call self(prop, +that new thing, encounteredObjects.concat(original)
   }
4. searls

   closed this as completedin #268on Jun 24, 2017
5. searls commented on Jun 24, 2017

   

   searls

   on Jun 24, 2017

   MemberAuthor

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   Landed in 3.2.0
6. searls

   added a commit that references this issue on Jul 21, 2017

   This is blocked by #262 b/c I can't fake log

   527ab97