fix: Updated Python types generation to be more PEP8 compliant

src/python.ts

@@ -7,6 +7,8 @@ import path from 'path'
 import fs from 'fs-extra'
 import { read, types, props, Schema, unions } from './bindings'
 
+const MAX_LINE_LENGTH = 75 // Desired max length - 4 to allow for indent
+
 /**
  * Run `build()` when this file is run as a Node script
  */
@@ -18,6 +20,11 @@ if (module.parent === null) build()
  */
 let globals: string[] = []
 
+/**
+ * Mapping between an enum signature (MD5 unique ID) and index
+ */
+const enumSignatures: Record<string, number> = {}
+
 /**
  * Generate `python/types.py` from schemas.
  */
@@ -33,8 +40,7 @@ async function build(): Promise<void> {
     .join('')
   const globalsCode = globals.join('\n')
 
-  const code = `
-from typing import Any, Dict, List as Array, Optional, Union
+  const code = `from typing import Any, Dict, List as Array, Optional, Union
 from enum import Enum
 
 ${globalsCode}
@@ -47,6 +53,36 @@ ${unionsCode}
   await fs.writeFile(path.join(__dirname, '..', 'python', 'types.py'), code)
 }
 
+/**
+ * Split a description into lines < MAX_LINE_LENGTH for PEP8 compliance.
+ * @param description
+ */
+function formatDocstring(description: string): string {
+  const lines: string[] = []
+  description = description.replace('\n', ' ').trim()
+
+  while (description.length > MAX_LINE_LENGTH) {
+    let splitIndex = MAX_LINE_LENGTH
+    for (; splitIndex > 0; --splitIndex) {
+      if (description.substr(splitIndex, 1) === ' ') {
+        lines.push(description.substring(0, splitIndex))
+        description = description.substring(splitIndex + 1)
+        break
+      }
+    }
+    if (splitIndex === 0) {
+      // reached the end without finding a space, split in the middle of word if we have to
+      description = description.substring(0, MAX_LINE_LENGTH)
+      if (description.length > MAX_LINE_LENGTH) {
+        // not at the end so push here and continue trimming
+        lines.push(description)
+      }
+    }
+  }
+  lines.push(description)
+  return lines.join('\n    ')
+}
+
 /**
  * Generate a `class`.
  */
@@ -55,7 +91,18 @@ export function classGenerator(schema: Schema): string {
   const { inherited, own, required, optional } = props(schema)
 
   const base = parent !== undefined ? '(' + parent + ')' : ''
-  const clas = `class ${title}${base}:\n    """\n    ${description}\n    """\n\n`
+  let docString = ''
+
+  if (description !== undefined) {
+    const formattedDescription = formatDocstring(description)
+    if (formattedDescription.length <= MAX_LINE_LENGTH - 6) {
+      docString = `    """${formattedDescription}"""\n\n` // docstring should fit on one line if it can
+    } else {
+      docString = `    """\n    ${formattedDescription}\n    """\n\n`
+    }
+  }
+
+  const clas = `class ${title}${base}:\n${docString}`
 
   const attrs = own
     .map(({ name, schema, optional }) => {
@@ -86,7 +133,10 @@ export function classGenerator(schema: Schema): string {
   const superCall = `        super().__init__(${superArgs})`
 
   const initSetters = own
-    .map(({ name }) => `        if ${name} is not None: self.${name} = ${name}`)
+    .map(
+      ({ name }) =>
+        `        if ${name} is not None:\n            self.${name} = ${name}`
+    )
     .join('\n')
 
   const init = `    def __init__(${initPars}) -> None:\n${superCall}\n${initSetters}\n\n`
@@ -181,10 +231,23 @@ export function enumToType(enu: (string | number)[]): string {
     .update(values)
     .digest('hex')
 
-  const name = `Enum${signature}`
-  const defn = `${name} = Enum("${signature}", [${values}])`
+  let enumIndex = Object.keys(enumSignatures).length
+  let enumExists = false
+
+  if (enumSignatures[signature] !== undefined) {
+    enumIndex = enumSignatures[signature]
+    enumExists = true
+  } else {
+    enumSignatures[signature] = enumIndex
+  }
+
+  const name = `Enum${enumIndex}`
+
+  if (!enumExists) {
+    const defn = `${name} = Enum("${enumIndex}", [${values}])\n`
 
-  if (!globals.includes(defn)) globals.push(defn)
+    if (!globals.includes(defn)) globals.push(defn)
+  }
 
   return `"${name}"`
 }