Add interpolateToCurve util method

src/diagrams/gitGraph/gitGraphRenderer.js

@@ -4,6 +4,7 @@ import * as d3 from 'd3'
 import db from './gitGraphAst'
 import gitGraphParser from './parser/gitGraph'
 import { logger } from '../../logger'
+import { interpolateToCurve } from '../../utils'
 
 let allCommitsDict = {}
 let branchNum
@@ -52,10 +53,7 @@ function svgCreateDefs (svg) {
 }
 
 function svgDrawLine (svg, points, colorIdx, interpolate) {
-  let curve = d3.curveBasis
-  if (interpolate === 'linear') {
-    curve = d3.curveLinear
-  }
+  const curve = interpolateToCurve(interpolate, d3.curveBasis)
   const color = config.branchColors[colorIdx % config.branchColors.length]
   const lineGen = d3.line()
     .x(function (d) {
@@ -73,6 +71,7 @@ function svgDrawLine (svg, points, colorIdx, interpolate) {
     .style('stroke-width', config.lineStrokeWidth)
     .style('fill', 'none')
 }
+
 // Pass in the element and its pre-transform coords
 function getElementCoords (element, coords) {
   coords = coords || element.node().getBBox()

src/utils.js

@@ -1,4 +1,4 @@
-import { logger } from './logger'
+import * as d3 from 'd3'
 
 /**
  * @function detectType
@@ -36,12 +36,10 @@ export const detectType = function (text) {
   }
 
   if (text.match(/^\s*classDiagram/)) {
-    logger.debug('Detected classDiagram syntax')
     return 'classDiagram'
   }
 
   if (text.match(/^\s*gitGraph/)) {
-    logger.debug('Detected gitGraph syntax')
     return 'gitGraph'
   }
   return 'graph'
@@ -61,7 +59,17 @@ export const isSubstringInArray = function (str, arr) {
   return -1
 }
 
+const interpolates = {
+  basis: d3.curveBasis,
+  linear: d3.curveLinear,
+  cardinal: d3.curveCardinal
+}
+export const interpolateToCurve = (interpolate, defaultCurve) => {
+  return interpolates[interpolate] || defaultCurve
+}
+
 export default {
   detectType,
-  isSubstringInArray
+  isSubstringInArray,
+  interpolateToCurve
 }