Adds exceptions (indeclinable and exceptions with full forms)

packages/yoastseo/spec/morphology/dutch/addAdjectiveSuffixesSpec.js

@@ -127,21 +127,21 @@ describe( "Adds adjective suffixes", () => {
 			"groeners",
 			"groenere",
 			"groeneres",
-		] );
+		], );
 	} );
 	it( "Adds comparative suffixes to a modified  Dutch stem", () => {
 		expect( addComparativeSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "zwak" ) ).toEqual( [
 			"zwakker",
 			"zwakkers",
 			"zwakkere",
 			"zwakkeres",
-		] );
+		], );
 	} );
 	it( "Adds superlative suffixes to a given Dutch stem", () => {
 		expect( addSuperlativeSuffixes( morphologyDataNL.adjectives, "groen" ) ).toEqual( [
 			"groenst",
 			"groenste",
-		] );
+		], );
 	} );
 	it( "Adds all adjective suffixes to a given Dutch stem", () => {
 		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "groen" ) ).toEqual( [
@@ -153,19 +153,7 @@ describe( "Adds adjective suffixes", () => {
 			"groenste",
 			"groene",
 			"groens",
-		] );
-	} );
-	it( "Adds all adjective suffixes to a given Dutch stem", () => {
-		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "zuiver" ) ).toEqual( [
-			"zuiverder",
-			"zuiverders",
-			"zuiverdere",
-			"zuiverderes",
-			"zuiverst",
-			"zuiverste",
-			"zuivere",
-			"zuivers",
-		] );
+		], );
 	} );
 	it( "Does not make a partitive form if stem ends with an s", () => {
 		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "boos" ) ).toEqual( [
@@ -176,7 +164,7 @@ describe( "Adds adjective suffixes", () => {
 			"boost",
 			"booste",
 			"boze",
-		] );
+		], );
 	} );
 	it( "Adds all adjective suffixes to a given Dutch stem that requires stem modifications", () => {
 		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "hoog" ) ).toEqual( [
@@ -188,31 +176,6 @@ describe( "Adds adjective suffixes", () => {
 			"hoogste",
 			"hoge",
 			"hoogs",
-		] );
-	} );
-	it( "Adds all adjective suffixes to a given Dutch stem that normally requires stem modifications but doesn't", () => {
-		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "nobel" ) ).toEqual( [
-			"nobeler",
-			"nobelers",
-			"nobelere",
-			"nobeleres",
-			"nobelst",
-			"nobelste",
-			"nobele",
-			"nobels",
-		] );
-	} );
-	it( "Adds all adjective suffixes to a given Dutch stem that normally requires stem modifications but doesn't " +
-		"Input: word ends in one of the words in the exception list (verb)", () => {
-		expect( addAllAdjectiveSuffixes( morphologyDataNL.adjectives, morphologyDataNL.addSuffixes.stemModifications, "memorabel" ) ).toEqual( [
-			"memorabeler",
-			"memorabelers",
-			"memorabelere",
-			"memorabeleres",
-			"memorabelst",
-			"memorabelste",
-			"memorabele",
-			"memorabels",
-		] );
+		], );
 	} );
 } );

packages/yoastseo/spec/morphology/dutch/addNounSuffixesSpec.js

@@ -25,7 +25,7 @@ describe( "Test for getting the right plural suffixes", () => {
 		] );
 	} );
 	it( "returns the default plural suffix if no suffix could be predicted based on stem ending", () => {
-		expect( getSuffixes( "bal", morphologyDataNL.nouns.suffixes.pluralSuffixes ) ).toEqual( [
+		expect( getSuffixes( "groent", morphologyDataNL.nouns.suffixes.pluralSuffixes ) ).toEqual( [
 			"en",
 		] );
 	} );

packages/yoastseo/spec/morphology/morphoHelpers/checkExceptionsWithFullFormsSpec.js

@@ -0,0 +1,24 @@
+import checkExceptionsWithFullForms  from "../../../src/morphology/morphoHelpers/checkExceptionsWithFullForms";
+import getMorphologyData from "../../specHelpers/getMorphologyData";
+
+const morphologyDataNL = getMorphologyData( "nl" ).nl;
+
+describe( "Test for getting the correct stem from full forms exception lists", () => {
+	it( "return the correct stem when the word checked is listed in the full form exception list", () => {
+		expect( checkExceptionsWithFullForms( morphologyDataNL.stemming.stemmingExceptionStemsWithFullForms, "stadje" ) ).toEqual( "stad" );
+	} );
+	it( "return the correct stem when the word checked is listed in the full form exception list", () => {
+		expect( checkExceptionsWithFullForms( morphologyDataNL.stemming.stemmingExceptionStemsWithFullForms, "museumpjes" ) ).toEqual( "museum" );
+	} );
+	it( "return the correct stem when the word checked is a compound word ending in a word listed in the full form exception list", () => {
+		expect( checkExceptionsWithFullForms( morphologyDataNL.stemming.stemmingExceptionStemsWithFullForms, "fitnesscentra" ) ).toEqual(
+			"fitnesscentrum" );
+	} );
+	it( "returns null if the word ends in a word from the exception list ('eis'), but the preceding lexical material is shorter" +
+		" than 2 characters", () => {
+		expect( checkExceptionsWithFullForms( morphologyDataNL.stemming.stemmingExceptionStemsWithFullForms, "reis" ) ).toEqual( null );
+	} );
+	it( "returns null if the word checked is not in the exception list", () => {
+		expect( checkExceptionsWithFullForms( morphologyDataNL.stemming.stemmingExceptionStemsWithFullForms, "plant" ) ).toEqual( null );
+	} );
+} );

packages/yoastseo/src/morphology/morphoHelpers/checkExceptionsWithFullForms.js

@@ -0,0 +1,33 @@
+import { flatten } from "lodash-es";
+/**
+ *
+ * Checks whether a word is on the exception list for which we have full forms. If it is, returns the indicated stem of the word.
+ *
+ * @param {Array} fullFormsExceptionList The exception list with full forms to check against.
+ * @param {string} word The word to check.
+ *
+ * @returns {string/null} The created word forms.
+ */
+export default function( fullFormsExceptionList, word ) {
+	for ( let i = 0; i < fullFormsExceptionList.length; i++ ) {
+		const stemAndForms = flatten( fullFormsExceptionList[ i ] );
+		for ( let j = 0; j < stemAndForms.length; j++ ) {
+			if ( word.endsWith( stemAndForms[ j ] ) ) {
+				/*
+				 * Check if the word checked is actually a compound word. e.g. familielid
+				 * The character/s preceding the words in the exception should be at least 2 characters in order to be a valid compound element.
+				 */
+				const precedingLexicalMaterial = word.slice( 0, -stemAndForms[ j ].length );
+				if ( precedingLexicalMaterial.length === 1 ) {
+					return null;
+				}
+				// We only need to return the first index of the array as the stem.
+				if ( precedingLexicalMaterial.length > 1 ) {
+					return precedingLexicalMaterial.concat( stemAndForms[ 0 ] );
+				}
+				return stemAndForms[ 0 ];
+			}
+		}
+	}
+	return null;
+}