mirror of
https://github.com/LukeHagar/libopenapi.git
synced 2025-12-06 04:20:11 +00:00
Updated readme.
This commit is contained in:
760
README.md
760
README.md
@@ -30,6 +30,7 @@ like our _very kind_ sponsors:
|
||||
|
||||
- [github.com/danielgtaylor/restish](https://github.com/danielgtaylor/restish) - "Restish is a CLI for interacting with REST-ish HTTP APIs"
|
||||
- [github.com/daveshanley/vacuum](https://github.com/daveshanley/vacuum) - "The world's fastest and most scalable OpenAPI/Swagger linter/quality tool"
|
||||
- [github.com/pb33f/openapi-changes](https://github.com/pb33f/openapi-changes) - "The world's **sexiest** OpenAPI diff tool"
|
||||
|
||||
---
|
||||
|
||||
@@ -38,82 +39,25 @@ like our _very kind_ sponsors:
|
||||
Need help? Have a question? Want to share your work? [Join our discord](https://discord.gg/x7VACVuEGP) and
|
||||
come say hi!
|
||||
|
||||
## Contents
|
||||
## Documentation
|
||||
|
||||
- [Installing libopenapi](#installing)
|
||||
- [Load an OpenAPI 3.1 or 3.0 specification into a model](#load-an-openapi-spec-into-a-model)
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||||
- [Load a Swagger Spec into a model](#load-a-swagger-spec-into-a-model)
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||||
- [Discover what changed](#discover-what-changed)
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||||
- [Loading complex types using extensions](#loading-extensions-using-complex-types)
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||||
- [Creating an index of an OpenAPI specification](#creating-an-index-of-an-openapi-specification)
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- [Resolving an OpenAPI specification](#resolving-an-openapi-specification)
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- [Checking for circular errors without resolving](#checking-for-circular-errors-without-resolving)
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- [Extracting circular refs and resolving errors when building a document](#extracting-circular-refs-and-resolving-errors-when-building-a-document)
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- [Mutating the model](#mutating-the-model)
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See all the documentation at https://pb33f.io/libopenapi/
|
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|
||||
> **Read the docs at [https://pkg.go.dev/github.com/pb33f/libopenapi](https://pkg.go.dev/github.com/pb33f/libopenapi)**
|
||||
>
|
||||
- [Installing libopenapi](https://pb33f.io/libopenapi/installing/)
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- [Using OpenAPI](https://pb33f.io/libopenapi/openapi/)
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- [Using Swagger](https://pb33f.io/libopenapi/swagger/)
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- [The Data Model](https://pb33f.io/libopenapi/model/)
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- [Using Vendor Extensions](https://pb33f.io/libopenapi/extensions/)
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- [The Index](https://pb33f.io/libopenapi/index/)
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- [The Resolver](https://pb33f.io/libopenapi/resolver/)
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- [Circular References](https://pb33f.io/libopenapi/circular-references/)
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||||
- [What Changed / Diff Engine](https://pb33f.io/libopenapi/what-changed/)
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||||
- [FAQ](https://pb33f.io/libopenapi/faq/)
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- [About libopenapi](https://pb33f.io/libopenapi/about/)
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> **Read the go docs at [https://pkg.go.dev/github.com/pb33f/libopenapi](https://pkg.go.dev/github.com/pb33f/libopenapi)**
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---
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## Introduction - Why?
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There is already a really great OpenAPI library for golang, it's called [kin-openapi](https://github.com/getkin/kin-openapi).
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|
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### Why does `libopenapi` exist?
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[kin-openapi](https://github.com/getkin/kin-openapi) is great, and you should go and use it.
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|
||||
#### If you're still reading, here is why `libopenapi` might be useful.
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> **_kin-openapi missing a few critical features_**... They are so important, this entire toolset was created to address
|
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> those gaps.
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When building tooling that needs to analyze OpenAPI specifications at a *low* level, [kin-openapi](https://github.com/getkin/kin-openapi)
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**runs out of power** when you need to know the original line numbers and columns, or comments within all keys and values
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in the specification.
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|
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All that data is **lost** when the OpenAPI specification is loaded in by [kin-openapi](https://github.com/getkin/kin-openapi).
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Mainly because the library will unmarshal data **directly into structs**, which works great - if you **_don't_** need
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access to the original specification low level details.
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|
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### Why not just modify kin-openapi?
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It would require a fundamental re-build of the entire library, with a different design to expose the same functionality.
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---
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## libopenapi retains _everything_.
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`libopenapi` has been designed to retain all of that really low-level detail about the AST, line numbers, column numbers,
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comments, original AST structure - everything you could need.
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|
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`libopenapi` has a **porcelain** (high-level) and a **plumbing** (low-level) API. Every high level struct, has the
|
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ability to `GoLow()` and dive from the high-level model, down to the low-level model and look-up any detail about the
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underlying raw data backing that model.
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|
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This library exists because this very need existed inside [VMware](https://vmware.com). The company built an internal
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version of `libopenapi`, which isn't something that can be released as it's customized for VMware (and it's incomplete).
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`libopenapi` is the result of years of learning and battle testing OpenAPI in golang. This library represents what would
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have been created, if we knew then - what we know now.
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## what-changed: a complete diff engine
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|
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Compare Swagger and OpenAPI documents for all changes made across the specification. Every detail is checked across
|
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all versions of OpenAPI and returns a simple to navigate report of every single change made.
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|
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Everything modified, added or removed is reported, complete with original/new values, line numbers and columns.
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> Need to know which **line**, or **column** number a key or value for something is? **`libopenapi` has you covered**.
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## Comes with an Index and a Resolver
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|
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Want a lightning fast way to look up any element in an OpenAPI swagger spec? **`libopenapi` has you covered**.
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Need a way to 'resolve' OpenAPI documents that are exploded out across multiple files, remotely or locally?
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**`libopenapi` has you covered**.
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|
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---
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### Quick-start tutorial
|
||||
|
||||
👀 **Get rolling fast using `libopenapi` with the
|
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@@ -123,676 +67,4 @@ Need a way to 'resolve' OpenAPI documents that are exploded out across multiple
|
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|
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---
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## Installing
|
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Grab the latest release of **libopenapi**
|
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|
||||
```
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go get github.com/pb33f/libopenapi
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```
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## Load an OpenAPI spec into a model
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|
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```go
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// import the library
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import "github.com/pb33f/libopenapi"
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func readSpec() {
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|
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// load an OpenAPI 3 specification from bytes
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petstore, _ := ioutil.ReadFile("test_specs/petstorev3.json")
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// create a new document from specification bytes
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document, err := libopenapi.NewDocument(petstore)
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// if anything went wrong, an error is thrown
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if err != nil {
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panic(fmt.Sprintf("cannot create new document: %e", err))
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}
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// because we know this is a v3 spec, we can build a ready to go model from it.
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v3Model, errors := document.BuildV3Model()
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// if anything went wrong when building the v3 model, a slice of errors will be returned
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if len(errors) > 0 {
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for i := range errors {
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fmt.Printf("error: %e\n", errors[i])
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}
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panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported",
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len(errors)))
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}
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// get a count of the number of paths and schemas.
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paths := len(v3Model.Model.Paths.PathItems)
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schemas := len(v3Model.Model.Components.Schemas)
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||||
|
||||
// print the number of paths and schemas in the document
|
||||
fmt.Printf("There are %d paths and %d schemas in the document", paths, schemas)
|
||||
}
|
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```
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|
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This will print:
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|
||||
```
|
||||
There are 13 paths and 8 schemas in the document
|
||||
```
|
||||
|
||||
|
||||
## Load a Swagger spec into a model
|
||||
```go
|
||||
// import the library
|
||||
import "github.com/pb33f/libopenapi"
|
||||
|
||||
func readSpec() {
|
||||
|
||||
// load a Swagger specification from bytes
|
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petstore, _ := ioutil.ReadFile("test_specs/petstorev2.json")
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|
||||
// create a new document from specification bytes
|
||||
document, err := libopenapi.NewDocument(petstore)
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|
||||
// if anything went wrong, an error is thrown
|
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if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
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||||
|
||||
// because we know this is a v2 spec, we can build a ready to go model from it.
|
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v2Model, errors := document.BuildV2Model()
|
||||
|
||||
// if anything went wrong when building the v3 model, a slice of errors will be returned
|
||||
if len(errors) > 0 {
|
||||
for i := range errors {
|
||||
fmt.Printf("error: %e\n", errors[i])
|
||||
}
|
||||
panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported",
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len(errors)))
|
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}
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|
||||
// get a count of the number of paths and schemas.
|
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paths := len(v2Model.Model.Paths.PathItems)
|
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schemas := len(v2Model.Model.Definitions.Definitions)
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|
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// print the number of paths and schemas in the document
|
||||
fmt.Printf("There are %d paths and %d schemas in the document", paths, schemas)
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}
|
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```
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This will print:
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|
||||
```
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There are 14 paths and 6 schemas in the document
|
||||
```
|
||||
|
||||
### Dropping down from the high-level API to the low-level one
|
||||
|
||||
This example shows how after loading an OpenAPI spec into a document, navigating to an Operation is pretty simple.
|
||||
It then shows how to _drop-down_ (using `GoLow())` to the low-level API and query the line and start
|
||||
column of the RequestBody description.
|
||||
|
||||
```go
|
||||
// load an OpenAPI 3 specification from bytes
|
||||
petstore, _ := ioutil.ReadFile("test_specs/petstorev3.json")
|
||||
|
||||
// create a new document from specification bytes
|
||||
// (ignore errors for the same of the example)
|
||||
document, _ := libopenapi.NewDocument(petstore)
|
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|
||||
// because we know this is a v3 spec, we can build a ready to go model from it
|
||||
// (ignoring errors for the example)
|
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v3Model, _ := document.BuildV3Model()
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|
||||
// extract the RequestBody from the 'put' operation under the /pet path
|
||||
reqBody := document.Paths.PathItems["/pet"].Put.RequestBody
|
||||
|
||||
// dropdown to the low-level API for RequestBody
|
||||
lowReqBody := reqBody.GoLow()
|
||||
|
||||
// print out the value, the line it appears on and the
|
||||
// start columns for the key and value of the nodes.
|
||||
fmt.Printf("value is %s, the value is on line %d, " +
|
||||
"starting column %d, the key is on line %d, column %d",
|
||||
reqBody.Description,
|
||||
lowReqBody.Description.ValueNode.Line,
|
||||
lowReqBody.Description.ValueNode.Column,
|
||||
lowReqBody.Description.KeyNode.Line,
|
||||
lowReqBody.KeyNode.Column)
|
||||
```
|
||||
---
|
||||
|
||||
## Discover what changed
|
||||
|
||||
libopenapi comes with a complete **diff engine**
|
||||
|
||||
Want to know what changed between two different OpenAPI or Swagger specifications? libopenapi makes this super, super easy.
|
||||
|
||||
```go
|
||||
// How to compare two different OpenAPI specifications for changes between them.
|
||||
|
||||
// load an original OpenAPI 3 specification from bytes
|
||||
burgerShopOriginal, _ := ioutil.ReadFile("test_specs/burgershop.openapi.yaml")
|
||||
|
||||
// load an **updated** OpenAPI 3 specification from bytes
|
||||
burgerShopUpdated, _ := ioutil.ReadFile("test_specs/burgershop.openapi-modified.yaml")
|
||||
|
||||
// create a new document from original specification bytes
|
||||
originalDoc, err := NewDocument(burgerShopOriginal)
|
||||
|
||||
// if anything went wrong, an error is thrown
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
|
||||
|
||||
// create a new document from updated specification bytes
|
||||
updatedDoc, err := NewDocument(burgerShopUpdated)
|
||||
|
||||
// if anything went wrong, an error is thrown
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
|
||||
|
||||
// Compare documents for all changes made
|
||||
documentChanges, errs := CompareDocuments(originalDoc, updatedDoc)
|
||||
|
||||
// If anything went wrong when building models for documents.
|
||||
if len(errs) > 0 {
|
||||
for i := range errs {
|
||||
fmt.Printf("error: %e\n", errs[i])
|
||||
}
|
||||
panic(fmt.Sprintf("cannot compare documents: %d errors reported", len(errs)))
|
||||
}
|
||||
|
||||
// Extract SchemaChanges from components changes.
|
||||
schemaChanges := documentChanges.ComponentsChanges.SchemaChanges
|
||||
|
||||
// Print out some interesting stats about the OpenAPI document changes.
|
||||
fmt.Printf("There are %d changes, of which %d are breaking. %v schemas have changes.",
|
||||
documentChanges.TotalChanges(), documentChanges.TotalBreakingChanges(), len(schemaChanges))
|
||||
|
||||
```
|
||||
|
||||
Every change can be explored and navigated just like you would use the high or low level models.
|
||||
|
||||
---
|
||||
|
||||
## Loading extensions using complex types
|
||||
|
||||
If you're using extensions with complex types (rather that just simple strings and primitives), then there is a good
|
||||
chance you're going to want some simple way to marshal extensions into those structs.
|
||||
|
||||
Since version v0.3.2 There is a new method to make this simple available in the `high` package within the `datamodel`
|
||||
package. It's called `UnpackExtensions`
|
||||
|
||||
It's a generic function that requires the custom type and the **low** model type of the object that contains the extensions
|
||||
you'd like to unpack.
|
||||
|
||||
Here is an example of complex types being extracted easily from OpenAPI extensions.
|
||||
|
||||
```go
|
||||
|
||||
import (
|
||||
"github.com/pb33f/libopenapi"
|
||||
high "github.com/pb33f/libopenapi/datamodel/high"
|
||||
lowbase "github.com/pb33f/libopenapi/datamodel/low/base"
|
||||
lowv3 "github.com/pb33f/libopenapi/datamodel/low/v3"
|
||||
)
|
||||
|
||||
// define an example struct representing a cake
|
||||
// super important to remember to use hints/meta-data to map properties correctly.
|
||||
type cake struct {
|
||||
Candles int `yaml:"candles"`
|
||||
Frosting string `yaml:"frosting"`
|
||||
Some_Strange_Var_Name string `yaml:"someStrangeVarName"`
|
||||
}
|
||||
|
||||
// define a struct that holds a map of cake pointers.
|
||||
type cakes struct {
|
||||
Description string
|
||||
Cakes map[string]*cake
|
||||
}
|
||||
|
||||
// define a struct representing a burger
|
||||
type burger struct {
|
||||
Sauce string
|
||||
Patty string
|
||||
}
|
||||
|
||||
// define a struct that holds a map of cake pointers
|
||||
type burgers struct {
|
||||
Description string
|
||||
Burgers map[string]*burger
|
||||
}
|
||||
|
||||
func main() {
|
||||
|
||||
// create a specification with a schema and parameter that use complex
|
||||
// custom cakes and burgers extensions.
|
||||
spec := `openapi: "3.1"
|
||||
components:
|
||||
schemas:
|
||||
SchemaOne:
|
||||
description: "Some schema with custom complex extensions"
|
||||
x-custom-cakes:
|
||||
description: some cakes
|
||||
cakes:
|
||||
someCake:
|
||||
candles: 10
|
||||
frosting: blue
|
||||
someStrangeVarName: mapping is required to extract these.
|
||||
anotherCake:
|
||||
candles: 1
|
||||
frosting: green
|
||||
parameters:
|
||||
ParameterOne:
|
||||
description: "Some parameter also using complex extensions"
|
||||
x-custom-burgers:
|
||||
description: some burgers
|
||||
burgers:
|
||||
someBurger:
|
||||
sauce: ketchup
|
||||
patty: meat
|
||||
anotherBurger:
|
||||
sauce: mayo
|
||||
patty: lamb`
|
||||
|
||||
// create a new document from specification bytes
|
||||
doc, err := libopenapi.NewDocument([]byte(spec))
|
||||
|
||||
// if anything went wrong, an error is thrown
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
|
||||
|
||||
// build a v3 model.
|
||||
docModel, errs := doc.BuildV3Model()
|
||||
|
||||
// if anything went wrong building, indexing and resolving the model, errors are thrown.
|
||||
if errs != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", errs))
|
||||
}
|
||||
|
||||
// get a reference to SchemaOne and ParameterOne
|
||||
schemaOne := docModel.Model.Components.Schemas["SchemaOne"].Schema()
|
||||
parameterOne := docModel.Model.Components.Parameters["ParameterOne"]
|
||||
|
||||
// unpack schemaOne extensions into complex `cakes` type
|
||||
schemaOneExtensions, schemaUnpackErrors := high.UnpackExtensions[cakes, *lowbase.Schema](schemaOne)
|
||||
if schemaUnpackErrors != nil {
|
||||
panic(fmt.Sprintf("cannot unpack schema extensions: %e", err))
|
||||
}
|
||||
|
||||
// unpack parameterOne into complex `burgers` type
|
||||
parameterOneExtensions, paramUnpackErrors := high.UnpackExtensions[burgers, *lowv3.Parameter](parameterOne)
|
||||
if paramUnpackErrors != nil {
|
||||
panic(fmt.Sprintf("cannot unpack parameter extensions: %e", err))
|
||||
}
|
||||
|
||||
// extract extension by name for schemaOne
|
||||
customCakes := schemaOneExtensions["x-custom-cakes"]
|
||||
|
||||
// extract extension by name for schemaOne
|
||||
customBurgers := parameterOneExtensions["x-custom-burgers"]
|
||||
|
||||
// print out schemaOne complex extension details.
|
||||
fmt.Printf("schemaOne 'x-custom-cakes' (%s) has %d cakes, 'someCake' has %d candles and %s frosting\n",
|
||||
customCakes.Description,
|
||||
len(customCakes.Cakes),
|
||||
customCakes.Cakes["someCake"].Candles,
|
||||
customCakes.Cakes["someCake"].Frosting,
|
||||
)
|
||||
|
||||
// print out parameterOne complex extension details.
|
||||
fmt.Printf("parameterOne 'x-custom-burgers' (%s) has %d burgers, 'anotherBurger' has %s sauce and a %s patty\n",
|
||||
customBurgers.Description,
|
||||
len(customBurgers.Burgers),
|
||||
customBurgers.Burgers["anotherBurger"].Sauce,
|
||||
customBurgers.Burgers["anotherBurger"].Patty,
|
||||
)
|
||||
}
|
||||
```
|
||||
|
||||
This will output:
|
||||
|
||||
```text
|
||||
schemaOne 'x-custom-cakes' (some cakes) has 2 cakes, 'someCake' has 10 candles and blue frosting
|
||||
parameterOne 'x-custom-burgers' (some burgers) has 2 burgers, 'anotherBurger' has mayo sauce and a lamb patty
|
||||
```
|
||||
---
|
||||
|
||||
## Creating an index of an OpenAPI Specification
|
||||
|
||||
An index is really useful when a map of an OpenAPI spec is needed. Knowing where all the references are and where
|
||||
they point, is very useful when resolving specifications, or just looking things up.
|
||||
|
||||
### Creating an index from the Stripe OpenAPI Spec
|
||||
|
||||
```go
|
||||
// define a rootNode to hold our raw stripe spec AST.
|
||||
var rootNode yaml.Node
|
||||
|
||||
// load in the stripe OpenAPI specification into bytes (it's pretty meaty)
|
||||
stripeSpec, _ := ioutil.ReadFile("test_specs/stripe.yaml")
|
||||
|
||||
// unmarshal spec into our rootNode
|
||||
yaml.Unmarshal(stripeSpec, &rootNode)
|
||||
|
||||
// create a new specification index.
|
||||
index := index.NewSpecIndex(&rootNode)
|
||||
|
||||
// print out some statistics
|
||||
fmt.Printf("There are %d references\n"+
|
||||
"%d paths\n"+
|
||||
"%d operations\n"+
|
||||
"%d schemas\n"+
|
||||
"%d enums\n"+
|
||||
"%d polymorphic references",
|
||||
len(index.GetAllCombinedReferences()),
|
||||
len(index.GetAllPaths()),
|
||||
index.GetOperationCount(),
|
||||
len(index.GetAllSchemas()),
|
||||
len(index.GetAllEnums()),
|
||||
len(index.GetPolyOneOfReferences())+len(index.GetPolyAnyOfReferences()))
|
||||
```
|
||||
|
||||
## Resolving an OpenAPI Specification
|
||||
|
||||
When creating an index, the raw AST that uses [yaml.Node](https://pkg.go.dev/gopkg.in/yaml.v3#Node) is preserved
|
||||
when looking up local, file-based and remote references. This means that if required, the spec can be 'resolved'
|
||||
and all the reference nodes will be replaced with the actual data they reference.
|
||||
|
||||
What this looks like from a spec perspective.
|
||||
|
||||
If the specification looks like this:
|
||||
|
||||
```yaml
|
||||
paths:
|
||||
"/some/path/to/a/thing":
|
||||
get:
|
||||
responses:
|
||||
"200":
|
||||
$ref: '#/components/schemas/MySchema'
|
||||
components:
|
||||
schemas:
|
||||
MySchema:
|
||||
type: string
|
||||
description: This is my schema that is great!
|
||||
```
|
||||
|
||||
Will become this (as represented by the root [yaml.Node](https://pkg.go.dev/gopkg.in/yaml.v3#Node)
|
||||
|
||||
```yaml
|
||||
paths:
|
||||
"/some/path/to/a/thing":
|
||||
get:
|
||||
responses:
|
||||
"200":
|
||||
type: string
|
||||
description: This is my schema that is great!
|
||||
components:
|
||||
schemas:
|
||||
MySchema:
|
||||
type: string
|
||||
description: This is my schema that is great!
|
||||
```
|
||||
> This is not a valid spec, it's just design to illustrate how resolving works.
|
||||
|
||||
The reference has been 'resolved', so when reading the raw AST, there is no lookup required anymore.
|
||||
|
||||
### Resolving Example:
|
||||
|
||||
Using the Stripe API as an example, we can resolve all references, and then count how many circular reference issues
|
||||
were found.
|
||||
|
||||
```go
|
||||
import (
|
||||
"github.com/pb33f/libopenapi/index"
|
||||
"github.com/pb33f/libopenapi/resolver"
|
||||
)
|
||||
|
||||
// create a yaml.Node reference as a root node.
|
||||
var rootNode yaml.Node
|
||||
|
||||
// load in the Stripe OpenAPI spec (lots of polymorphic complexity in here)
|
||||
stripeBytes, _ := ioutil.ReadFile("../test_specs/stripe.yaml")
|
||||
|
||||
// unmarshal bytes into our rootNode.
|
||||
_ = yaml.Unmarshal(stripeBytes, &rootNode)
|
||||
|
||||
// create a new spec index (resolver depends on it)
|
||||
index := index.NewSpecIndex(&rootNode)
|
||||
|
||||
// create a new resolver using the index.
|
||||
resolver := resolver.NewResolver(index)
|
||||
|
||||
// resolve the document, if there are circular reference errors, they are returned/
|
||||
// WARNING: this is a destructive action and the rootNode will be
|
||||
// PERMANENTLY altered and cannot be unresolved
|
||||
circularErrors := resolver.Resolve()
|
||||
|
||||
// The Stripe API has a bunch of circular reference problems,
|
||||
// mainly from polymorphism. So let's print them out.
|
||||
fmt.Printf("There are %d circular reference errors, " +
|
||||
"%d of them are polymorphic errors, %d are not",
|
||||
len(circularErrors),
|
||||
len(resolver.GetPolymorphicCircularErrors()),
|
||||
len(resolver.GetNonPolymorphicCircularErrors()))
|
||||
```
|
||||
|
||||
This will output:
|
||||
|
||||
`There are 21 circular reference errors, 19 of them are polymorphic errors, 2 are not`
|
||||
|
||||
> Important to remember: Resolving is **destructive** and will permanently change the tree, it cannot be un-resolved.
|
||||
|
||||
### Checking for circular errors without resolving
|
||||
|
||||
Resolving is destructive, the original reference nodes are gone and all replaced, so how do we check for circular references
|
||||
in a non-destructive way? Instead of calling `Resolve()`, we can call `CheckForCircularReferences()` instead.
|
||||
|
||||
The same code as `Resolve()` executes, except the tree is **not actually resolved**, _nothing_ changes and _no destruction_
|
||||
occurs. A handy way to perform circular reference analysis on the specification, without permanently altering it.
|
||||
|
||||
```go
|
||||
import (
|
||||
"github.com/pb33f/libopenapi/index"
|
||||
"github.com/pb33f/libopenapi/resolver"
|
||||
)
|
||||
|
||||
// create a yaml.Node reference as a root node.
|
||||
var rootNode yaml.Node
|
||||
|
||||
// load in the Stripe OpenAPI spec (lots of polymorphic complexity in here)
|
||||
stripeBytes, _ := ioutil.ReadFile("../test_specs/stripe.yaml")
|
||||
|
||||
// unmarshal bytes into our rootNode.
|
||||
_ = yaml.Unmarshal(stripeBytes, &rootNode)
|
||||
|
||||
// create a new spec index (resolver depends on it)
|
||||
index := index.NewSpecIndex(&rootNode)
|
||||
|
||||
// create a new resolver using the index.
|
||||
resolver := resolver.NewResolver(index)
|
||||
|
||||
// extract circular reference errors without any changes to the original tree.
|
||||
circularErrors := resolver.CheckForCircularReferences()
|
||||
|
||||
// The Stripe API has a bunch of circular reference problems,
|
||||
// mainly from polymorphism. So let's print them out.
|
||||
fmt.Printf("There are %d circular reference errors, " +
|
||||
"%d of them are polymorphic errors, %d are not",
|
||||
len(circularErrors),
|
||||
len(resolver.GetPolymorphicCircularErrors()),
|
||||
len(resolver.GetNonPolymorphicCircularErrors()))
|
||||
```
|
||||
|
||||
### Extracting circular refs and resolving errors when building a document
|
||||
|
||||
To avoid having to create an index and a resolver each time you want to both create
|
||||
a document and resolve it / check for errors, don't worry, circular references are checked
|
||||
automatically and are available in the returned `[]errors` which building a document.
|
||||
|
||||
The errors returned by the slice are pointers to `*resolver.ResolvingError` which contains
|
||||
rich details about the issue, where it was found and the journey it took to get there.
|
||||
|
||||
Here is an example:
|
||||
|
||||
```go
|
||||
// create a specification with an obvious and deliberate circular reference
|
||||
spec := `
|
||||
openapi: "3.1"
|
||||
components:
|
||||
schemas:
|
||||
One:
|
||||
description: "test one"
|
||||
properties:
|
||||
things:
|
||||
"$ref": "#/components/schemas/Two"
|
||||
Two:
|
||||
description: "test two"
|
||||
properties:
|
||||
testThing:
|
||||
"$ref": "#/components/schemas/One"
|
||||
`
|
||||
// create a new document from specification bytes
|
||||
doc, err := NewDocument([]byte(spec))
|
||||
|
||||
// if anything went wrong, an error is thrown
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
|
||||
_, errs := doc.BuildV3Model()
|
||||
|
||||
// extract resolving error
|
||||
resolvingError := errs[0]
|
||||
|
||||
// resolving error is a pointer to *resolver.ResolvingError
|
||||
// which provides access to rich details about the error.
|
||||
circularReference := resolvingError.(*resolver.ResolvingError).CircularReference
|
||||
|
||||
// capture the journey with all details
|
||||
var buf strings.Builder
|
||||
for n := range circularReference.Journey {
|
||||
|
||||
// add the full definition name to the journey.
|
||||
buf.WriteString(circularReference.Journey[n].Definition)
|
||||
if n < len(circularReference.Journey)-1 {
|
||||
buf.WriteString(" -> ")
|
||||
}
|
||||
}
|
||||
|
||||
// print out the journey and the loop point.
|
||||
fmt.Printf("Journey: %s\n", buf.String())
|
||||
fmt.Printf("Loop Point: %s", circularReference.LoopPoint.Definition)
|
||||
```
|
||||
|
||||
Will output:
|
||||
|
||||
```text
|
||||
Journey: #/components/schemas/Two -> #/components/schemas/One -> #/components/schemas/Two
|
||||
Loop Point: #/components/schemas/Two
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
|
||||
## Mutating the model
|
||||
|
||||
Having a read-only model is great, but what about when we want to modify the model and mutate values, or even add new
|
||||
content to the model? What if we also want to save that output as an updated specification - but we don't want to
|
||||
jumble up the original ordering of the source.
|
||||
|
||||
### marshaling and unmarshalling to and from structs into JSON/YAML is not ideal.
|
||||
|
||||
When we straight up use `json.Marshal` or `yaml.Marshal` to send structs to be rendered into the desired format, there
|
||||
is no guarantee as to the order in which each component will be rendered. This works great if...
|
||||
|
||||
- We don't care about the spec being randomly ordered.
|
||||
- We don't care about code-reviews.
|
||||
- We don't actually care about this very much.
|
||||
|
||||
### But if we do care...
|
||||
|
||||
Then libopenpi provides a way to mutate the model, that keeps the original [yaml.Node API](https://pkg.go.dev/gopkg.in/yaml.v3#Node)
|
||||
tree in-tact. It allows us to make changes to values in place, and serialize back to JSON or YAML without any changes to
|
||||
other content order.
|
||||
|
||||
```go
|
||||
// create very small, and useless spec that does nothing useful, except showcase this feature.
|
||||
spec := `
|
||||
openapi: 3.1.0
|
||||
info:
|
||||
title: This is a title
|
||||
contact:
|
||||
name: Some Person
|
||||
email: some@emailaddress.com
|
||||
license:
|
||||
url: http://some-place-on-the-internet.com/license
|
||||
`
|
||||
// create a new document from specification bytes
|
||||
document, err := libopenapi.NewDocument([]byte(spec))
|
||||
|
||||
// if anything went wrong, an error is thrown
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("cannot create new document: %e", err))
|
||||
}
|
||||
|
||||
// because we know this is a v3 spec, we can build a ready to go model from it.
|
||||
v3Model, errors := document.BuildV3Model()
|
||||
|
||||
// if anything went wrong when building the v3 model, a slice of errors will be returned
|
||||
if len(errors) > 0 {
|
||||
for i := range errors {
|
||||
fmt.Printf("error: %e\n", errors[i])
|
||||
}
|
||||
panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported", len(errors)))
|
||||
}
|
||||
|
||||
// mutate the title, to do this we currently need to drop down to the low-level API.
|
||||
v3Model.Model.GoLow().Info.Value.Title.Mutate("A new title for a useless spec")
|
||||
|
||||
// mutate the email address in the contact object.
|
||||
v3Model.Model.GoLow().Info.Value.Contact.Value.Email.Mutate("buckaroo@pb33f.io")
|
||||
|
||||
// mutate the name in the contact object.
|
||||
v3Model.Model.GoLow().Info.Value.Contact.Value.Name.Mutate("Buckaroo")
|
||||
|
||||
// mutate the URL for the license object.
|
||||
v3Model.Model.GoLow().Info.Value.License.Value.URL.Mutate("https://pb33f.io/license")
|
||||
|
||||
// serialize the document back into the original YAML or JSON
|
||||
mutatedSpec, serialError := document.Serialize()
|
||||
|
||||
// if something went wrong serializing
|
||||
if serialError != nil {
|
||||
panic(fmt.Sprintf("cannot serialize document: %e", serialError))
|
||||
}
|
||||
|
||||
// print our modified spec!
|
||||
fmt.Println(string(mutatedSpec))
|
||||
```
|
||||
|
||||
Which will output:
|
||||
|
||||
```yaml
|
||||
openapi: 3.1.0
|
||||
info:
|
||||
title: A new title for a useless spec
|
||||
contact:
|
||||
name: Buckaroo
|
||||
email: buckaroo@pb33f.io
|
||||
license:
|
||||
url: https://pb33f.io/license
|
||||
|
||||
```
|
||||
> It's worth noting that the original line numbers and column numbers **won't be respected** when calling `Serialize()`,
|
||||
> A new `Document` needs to be created from that raw YAML to continue processing after serialization.
|
||||
|
||||
> **Read the full docs at [https://pkg.go.dev](https://pkg.go.dev/github.com/pb33f/libopenapi)**
|
||||
|
||||
---
|
||||
|
||||
The library heavily depends on the fantastic (yet hard to get used to) [yaml.Node API](https://pkg.go.dev/gopkg.in/yaml.v3#Node).
|
||||
This is what is exposed by the `GoLow` API.
|
||||
|
||||
> It does not matter if the input material is JSON or YAML, the [yaml.Node API](https://pkg.go.dev/gopkg.in/yaml.v3#Node) supports both and
|
||||
> creates a great way to navigate the AST of the document.
|
||||
|
||||
Logo gopher is modified, originally from [egonelbre](https://github.com/egonelbre/gophers)
|
||||
|
||||
Reference in New Issue
Block a user