This repo is a programming exercise designed to practice Discovery Testing.
Configurator™ is a command-line tool that manages transforming, encrypting and decrypting configurations for a web application. It has two main functions: storage and retrieval of versioned archives from a key/value store webservice.
+-------------------+ +---------------------------------+ +--------------------------------------------+
| webapp configs | | configuration.archive | | key/value store webservice |
+-------------------+ +---------------------------------+ +--------------------------------------------+
| myapp | | files[config1.json]=7Yxi3bzz9ls | | myapp[configs:0.0.1]=myapp.configs.archive |
| config +----------> files[config2.yaml]=20xt639jfg1 +-> myapp[configs:0.0.2]=myapp.configs.archive |
| config1.json | | files[config3.js]=1337fhQwGads | | myapp[configs:0.0.3]=myapp.configs.archive |
| config2.yaml | | ... | | ... |
| config3.js | | | | |
+-------------------+ +---------------------------------+ +--------------------------------------------+
configurator store <app-identifier> <path-to-config-folder>
The storage portion of the CLI might be most easily understood via the following pseudocode:
store(appId, path)
readConfigsFrom(path)
for each config
encrypt(config)
write(archive)
keyValueStoreWebService.saveArchive(archive)
configurator fetch <app-identifier> [version:semver-string]
The retrieval portion of the CLI might be most easily understood via the following pseudocode:
fetch(appId, version=latest)
keyValueStoreWebService.getArchive(appId, version)
for each config in archive
decrypt(config)
write(decryptedConfig, configFilename)
Your task is to implement a solution to Configurator™ using the Discovery Testing Recursive Worfklow:
Discovery Testing prescribes a recursive workflow for TDD, seeking to defining a tree of objects to implement a feature
- Start by identifying an entry point and writing a collaboration test of it
- For each dependency the first collaboration test identifies:
- if it needs to be broken down further, write another collaboration test for it (e.g. GOTO 1)
- if its task is a straightforward data transformation, implement it as a pure-function leaf node
- if its task requires interaction with a third-party, implement a wrapper object
For Configurator™, that tree of objects might look something like this:
+---------------+
| |
| Configurator™ |
| |
+-------+-------+
|
+-------v-------+
+----------------| CLI |----------------+
| +---------------+ |
| | |
| | |
+--------------v--------+ +------------v--------+ +------------v---------+
| parsesCommandLineArgs | | storesConfiguration | | fetchesConfiguration |
+-----------------------+ +-------------------+-+ +-+--------------------+
| |
+---------------------+ | | +----------------+
| readsConfigurations |<---+ +--->| fetchesArchive |
+---------------------+ | | +----------------+
+------------------------+ | | +------------------------+
| encryptsConfigurations |<---+ +--->| decryptsConfigurations |
+------------------------+ | | +------------------------+
+---------------+ | | +----------------------+
| writesArchive |<---+ +----| writesConfigurations |
+---------------+ | +----------------------+
+---------------+ |
| storesArchive |<---+
+---------------+
- encryption and decryption can be done via base64 encoding/decoding
- interaction with the key/value store webservice can happen via a flatfile if that makes it easier
- If interaction with the key/value store webservice happens asynchronously how does that impact our tests?
- Can we write our tests such that they don't differ significantly when working with sync or async code?
- Are there any collaborators missing in the tree above?
- Are there any leaf nodes missing in the tree above?
- Which 3rd party libraries, if any, do you anticipate needing to integrate with?
- How would writing tests for nodes in the tree in reverse-order (from the bottom-up) affect the design of our code?
- spike out an actual simple key/val web service on something like firebase that can be regularly purged and used for this exercise
React
Typescript
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Alibaba
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