TemplateProcessor.java

package com.renomad.minum.templating;


import java.util.*;

/**
 * This class provides methods for working with templates.
 * <p>
 * The first step is to write a template.  Here is an example:
 * </p>
 * <pre>
 * Hello, my name is {{name}}
 * </pre>
 * <p>
 * Then, feed that string into the {@link #buildProcessor} method, like
 * this:
 * </p>
 * <pre>
 * {@code
 *   String input = "Hello, my name is {{name}}"
 *   TemplateProcessor helloProcessor = TemplateProcessor.buildProcessor(input);
 * }
 * </pre>
 * <p>
 * The returned value ("helloProcessor") can be rendered with different values. For
 * example:
 * </p>
 * <pre>
 * {@code
 *   Map<String,String> myMap = Map.of("name", "Susanne");
 *   String fullyRenderedString = helloProcessor.renderTemplate(myMap);
 * }
 * </pre>
 * <p>
 *     The result is:
 * </p>
 * <pre>
 *     {@code Hello, my name is Susanne}
 * </pre>
 */
public final class TemplateProcessor {

    private final List<TemplateSection> templateSections;

    /**
     * Instantiate a new object with a list of {@link TemplateSection}.
     */
    private TemplateProcessor(List<TemplateSection> templateSections) {
        this.templateSections = templateSections;
    }

    /**
     * Given a map of key names -> value, render a template.
     */
    public String renderTemplate(Map<String, String> myMap) {
        // This indicates the count of usages of each key
        Map <String, Integer> usageMap = new HashMap<>();
        List<String> parts = new ArrayList<>();
        for (TemplateSection templateSection : templateSections) {
            RenderingResult result = templateSection.render(myMap);
            parts.add(result.renderedSection());
            String appliedKey = result.appliedKey();
            if (appliedKey != null) {
                usageMap.merge(appliedKey, 1, Integer::sum);
            }
        }
        Set<String> unusedKeys = new HashSet<>(myMap.keySet());
        unusedKeys.removeIf(usageMap.keySet()::contains);

        if (!unusedKeys.isEmpty()) {
            throw new TemplateRenderException("No corresponding key in template found for these keys: " + String.join(", ", unusedKeys));
        }
        return String.join("",parts);
    }

    /**
     * Builds a {@link TemplateProcessor} from a string
     * containing a proper template.  Templated values
     * are surrounded by double-curly-braces, i.e. {{foo}} or {{ foo }}
     */
    public static TemplateProcessor buildProcessor(String template) {
        // this value holds the entire template after processing, comprised
        // of an ordered list of TemplateSections
        var tSections = new ArrayList<TemplateSection>();

        // these values are used for logging and setting proper indentation
        int rowNumber = 1;
        int columnNumber = 1;
        // this value records the indent of the beginning of template keys,
        // so we can properly indent the values later.
        int startOfKey = 0;

        StringBuilder builder = new StringBuilder();
        // this flag is to help us understand whether we are currently reading the
        // name of a template literal.
        // e.g. in the case of hello {{ name }}, "name" is the literal.
        boolean isInsideTemplateKeyLiteral = false;
        for (int i = 0; i < template.length(); i++) {
            char charAtCursor = template.charAt(i);

            if (justArrivedInside(template, charAtCursor, i)) {
                isInsideTemplateKeyLiteral = true;
                startOfKey = columnNumber;
                i += 1;
                builder = processSectionInside(builder, tSections);
            } else if (justArrivedOutside(template, charAtCursor, i, isInsideTemplateKeyLiteral)) {
                isInsideTemplateKeyLiteral = false;
                i += 1;
                builder = processSectionOutside(builder, tSections, startOfKey);
                startOfKey = 0;
            } else {
                builder.append(charAtCursor);

                /*
                 if we're at the end of the template, it's our last chance to
                 add a substring (we can't be adding to a key, since if we're
                 at the end, and it's not a closing brace, it's a malformed
                 template.
                 */
                if (i == template.length() - 1) {
                    if (isInsideTemplateKeyLiteral) {
                        // if we're exiting this string while inside a template literal, then
                        // we're reading a corrupted input, and we should make that clear
                        // to our caller.
                        String templateSample = template.length() > 10 ? template.substring(0, 10) + "..." : template;
                        throw new TemplateParseException(
                                "parsing failed for string starting with \"" + templateSample + "\" at line " + rowNumber + " and column " + columnNumber);
                    }
                    tSections.add(new TemplateSection(null, builder.toString(), 0));
                }
            }

            if (charAtCursor == '\n') {
                rowNumber += 1;
                columnNumber = 1;
            } else {
                columnNumber += 1;
            }

        }

        return new TemplateProcessor(tSections);
    }

    static StringBuilder processSectionInside(StringBuilder builder, List<TemplateSection> tSections) {
        if (!builder.isEmpty()) {
            tSections.add(new TemplateSection(null, builder.toString(), 0));
            builder = new StringBuilder();
        }
        return builder;
    }

    static StringBuilder processSectionOutside(StringBuilder builder, List<TemplateSection> tSections, int indent) {
        if (!builder.isEmpty()) {
            tSections.add(new TemplateSection(builder.toString().trim(), null, indent));
            builder = new StringBuilder();
        }
        return builder;
    }

    /**
     * Just left a template key value.
     * <pre>
     *     hello {{ world }}
     *                ^
     *                +------Template key
     *
     * </pre>
     */
    static boolean justArrivedOutside(String template, char charAtCursor, int i, boolean isInsideTemplateKeyLiteral) {
        return charAtCursor == '}' && (i + 1) < template.length() && template.charAt(i + 1) == '}' && isInsideTemplateKeyLiteral;
    }

    /**
     * Just arrived inside a template key value.
     * <pre>
     *     hello {{ world }}
     *                ^
     *                +------Template key
     *
     * </pre>
     */
    static boolean justArrivedInside(String template, char charAtCursor, int i) {
        return charAtCursor == '{' && (i + 1) < template.length() && template.charAt(i + 1) == '{';
    }
}
























Active mutators

CONDITIONALS_BOUNDARY
EMPTY_RETURNS
FALSE_RETURNS
INCREMENTS
INVERT_NEGS
MATH
NEGATE_CONDITIONALS
NULL_RETURNS
PRIMITIVE_RETURNS
TRUE_RETURNS
VOID_METHOD_CALLS

Tests examined

com.renomad.minum.templating.TemplatingTests (36 ms)
com.renomad.minum.FunctionalTests (1772 ms)
com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) (0 ms)
com.renomad.minum.templating.TemplateSectionTests.test_processSectionOutside_builderEmpty(com.renomad.minum.templating.TemplateSectionTests) (0 ms)
com.renomad.minum.templating.TemplateSectionTests.test_processSectionOutside_builderNotEmpty(com.renomad.minum.templating.TemplateSectionTests) (0 ms)

Report generated by PIT 1.17.0

1		package com.renomad.minum.templating;
2
3
4		import java.util.*;
5
6		/**
7		* This class provides methods for working with templates.
8		* <p>
9		* The first step is to write a template. Here is an example:
10		* </p>
11		* <pre>
12		* Hello, my name is {{name}}
13		* </pre>
14		* <p>
15		* Then, feed that string into the {@link #buildProcessor} method, like
16		* this:
17		* </p>
18		* <pre>
19		* {@code
20		* String input = "Hello, my name is {{name}}"
21		* TemplateProcessor helloProcessor = TemplateProcessor.buildProcessor(input);
22		* }
23		* </pre>
24		* <p>
25		* The returned value ("helloProcessor") can be rendered with different values. For
26		* example:
27		* </p>
28		* <pre>
29		* {@code
30		* Map<String,String> myMap = Map.of("name", "Susanne");
31		* String fullyRenderedString = helloProcessor.renderTemplate(myMap);
32		* }
33		* </pre>
34		* <p>
35		* The result is:
36		* </p>
37		* <pre>
38		* {@code Hello, my name is Susanne}
39		* </pre>
40		*/
41		public final class TemplateProcessor {
42
43		private final List<TemplateSection> templateSections;
44
45		/**
46		* Instantiate a new object with a list of {@link TemplateSection}.
47		*/
48		private TemplateProcessor(List<TemplateSection> templateSections) {
49		this.templateSections = templateSections;
50		}
51
52		/**
53		* Given a map of key names -> value, render a template.
54		*/
55		public String renderTemplate(Map<String, String> myMap) {
56		// This indicates the count of usages of each key
57		Map <String, Integer> usageMap = new HashMap<>();
58		List<String> parts = new ArrayList<>();
59		for (TemplateSection templateSection : templateSections) {
60		RenderingResult result = templateSection.render(myMap);
61		parts.add(result.renderedSection());
62		String appliedKey = result.appliedKey();
63	1 1. renderTemplate : negated conditional → KILLED	if (appliedKey != null) {
64		usageMap.merge(appliedKey, 1, Integer::sum);
65		}
66		}
67		Set<String> unusedKeys = new HashSet<>(myMap.keySet());
68		unusedKeys.removeIf(usageMap.keySet()::contains);
69
70	1 1. renderTemplate : negated conditional → KILLED	if (!unusedKeys.isEmpty()) {
71		throw new TemplateRenderException("No corresponding key in template found for these keys: " + String.join(", ", unusedKeys));
72		}
73	1 1. renderTemplate : replaced return value with "" for com/renomad/minum/templating/TemplateProcessor::renderTemplate → KILLED	return String.join("",parts);
74		}
75
76		/**
77		* Builds a {@link TemplateProcessor} from a string
78		* containing a proper template. Templated values
79		* are surrounded by double-curly-braces, i.e. {{foo}} or {{ foo }}
80		*/
81		public static TemplateProcessor buildProcessor(String template) {
82		// this value holds the entire template after processing, comprised
83		// of an ordered list of TemplateSections
84		var tSections = new ArrayList<TemplateSection>();
85
86		// these values are used for logging and setting proper indentation
87		int rowNumber = 1;
88		int columnNumber = 1;
89		// this value records the indent of the beginning of template keys,
90		// so we can properly indent the values later.
91		int startOfKey = 0;
92
93		StringBuilder builder = new StringBuilder();
94		// this flag is to help us understand whether we are currently reading the
95		// name of a template literal.
96		// e.g. in the case of hello {{ name }}, "name" is the literal.
97		boolean isInsideTemplateKeyLiteral = false;
98	2 1. buildProcessor : changed conditional boundary → KILLED 2. buildProcessor : negated conditional → KILLED	for (int i = 0; i < template.length(); i++) {
99		char charAtCursor = template.charAt(i);
100
101	1 1. buildProcessor : negated conditional → KILLED	if (justArrivedInside(template, charAtCursor, i)) {
102		isInsideTemplateKeyLiteral = true;
103		startOfKey = columnNumber;
104	1 1. buildProcessor : Changed increment from 1 to -1 → TIMED_OUT	i += 1;
105		builder = processSectionInside(builder, tSections);
106	1 1. buildProcessor : negated conditional → KILLED	} else if (justArrivedOutside(template, charAtCursor, i, isInsideTemplateKeyLiteral)) {
107		isInsideTemplateKeyLiteral = false;
108	1 1. buildProcessor : Changed increment from 1 to -1 → KILLED	i += 1;
109		builder = processSectionOutside(builder, tSections, startOfKey);
110		startOfKey = 0;
111		} else {
112		builder.append(charAtCursor);
113
114		/*
115		if we're at the end of the template, it's our last chance to
116		add a substring (we can't be adding to a key, since if we're
117		at the end, and it's not a closing brace, it's a malformed
118		template.
119		*/
120	2 1. buildProcessor : Replaced integer subtraction with addition → KILLED 2. buildProcessor : negated conditional → KILLED	if (i == template.length() - 1) {
121	1 1. buildProcessor : negated conditional → KILLED	if (isInsideTemplateKeyLiteral) {
122		// if we're exiting this string while inside a template literal, then
123		// we're reading a corrupted input, and we should make that clear
124		// to our caller.
125	2 1. buildProcessor : negated conditional → KILLED 2. buildProcessor : changed conditional boundary → KILLED	String templateSample = template.length() > 10 ? template.substring(0, 10) + "..." : template;
126		throw new TemplateParseException(
127		"parsing failed for string starting with \"" + templateSample + "\" at line " + rowNumber + " and column " + columnNumber);
128		}
129		tSections.add(new TemplateSection(null, builder.toString(), 0));
130		}
131		}
132
133	1 1. buildProcessor : negated conditional → KILLED	if (charAtCursor == '\n') {
134	1 1. buildProcessor : Changed increment from 1 to -1 → KILLED	rowNumber += 1;
135		columnNumber = 1;
136		} else {
137	1 1. buildProcessor : Changed increment from 1 to -1 → KILLED	columnNumber += 1;
138		}
139
140		}
141
142	1 1. buildProcessor : replaced return value with null for com/renomad/minum/templating/TemplateProcessor::buildProcessor → KILLED	return new TemplateProcessor(tSections);
143		}
144
145		static StringBuilder processSectionInside(StringBuilder builder, List<TemplateSection> tSections) {
146	1 1. processSectionInside : negated conditional → KILLED	if (!builder.isEmpty()) {
147		tSections.add(new TemplateSection(null, builder.toString(), 0));
148		builder = new StringBuilder();
149		}
150	1 1. processSectionInside : replaced return value with null for com/renomad/minum/templating/TemplateProcessor::processSectionInside → KILLED	return builder;
151		}
152
153		static StringBuilder processSectionOutside(StringBuilder builder, List<TemplateSection> tSections, int indent) {
154	1 1. processSectionOutside : negated conditional → KILLED	if (!builder.isEmpty()) {
155		tSections.add(new TemplateSection(builder.toString().trim(), null, indent));
156		builder = new StringBuilder();
157		}
158	1 1. processSectionOutside : replaced return value with null for com/renomad/minum/templating/TemplateProcessor::processSectionOutside → KILLED	return builder;
159		}
160
161		/**
162		* Just left a template key value.
163		* <pre>
164		* hello {{ world }}
165		* ^
166		* +------Template key
167		*
168		* </pre>
169		*/
170		static boolean justArrivedOutside(String template, char charAtCursor, int i, boolean isInsideTemplateKeyLiteral) {
171	8 1. justArrivedOutside : negated conditional → KILLED 2. justArrivedOutside : negated conditional → KILLED 3. justArrivedOutside : Replaced integer addition with subtraction → KILLED 4. justArrivedOutside : changed conditional boundary → KILLED 5. justArrivedOutside : negated conditional → KILLED 6. justArrivedOutside : replaced boolean return with true for com/renomad/minum/templating/TemplateProcessor::justArrivedOutside → KILLED 7. justArrivedOutside : Replaced integer addition with subtraction → KILLED 8. justArrivedOutside : negated conditional → KILLED	return charAtCursor == '}' && (i + 1) < template.length() && template.charAt(i + 1) == '}' && isInsideTemplateKeyLiteral;
172		}
173
174		/**
175		* Just arrived inside a template key value.
176		* <pre>
177		* hello {{ world }}
178		* ^
179		* +------Template key
180		*
181		* </pre>
182		*/
183		static boolean justArrivedInside(String template, char charAtCursor, int i) {
184	7 1. justArrivedInside : negated conditional → KILLED 2. justArrivedInside : negated conditional → KILLED 3. justArrivedInside : replaced boolean return with true for com/renomad/minum/templating/TemplateProcessor::justArrivedInside → KILLED 4. justArrivedInside : Replaced integer addition with subtraction → KILLED 5. justArrivedInside : negated conditional → KILLED 6. justArrivedInside : Replaced integer addition with subtraction → KILLED 7. justArrivedInside : changed conditional boundary → KILLED	return charAtCursor == '{' && (i + 1) < template.length() && template.charAt(i + 1) == '{';
185		}
186		}
187
		Mutations
63		1.1 Location : renderTemplate Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
70		1.1 Location : renderTemplate Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
73		1.1 Location : renderTemplate Killed by : com.renomad.minum.templating.TemplatingTests replaced return value with "" for com/renomad/minum/templating/TemplateProcessor::renderTemplate → KILLED
98		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests changed conditional boundary → KILLED 2.2 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
101		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
104		1.1 Location : buildProcessor Killed by : none Changed increment from 1 to -1 → TIMED_OUT
106		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
108		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests Changed increment from 1 to -1 → KILLED
120		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests Replaced integer subtraction with addition → KILLED 2.2 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
121		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
125		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED 2.2 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests changed conditional boundary → KILLED
133		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
134		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests Changed increment from 1 to -1 → KILLED
137		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests Changed increment from 1 to -1 → KILLED
142		1.1 Location : buildProcessor Killed by : com.renomad.minum.templating.TemplatingTests replaced return value with null for com/renomad/minum/templating/TemplateProcessor::buildProcessor → KILLED
146		1.1 Location : processSectionInside Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
150		1.1 Location : processSectionInside Killed by : com.renomad.minum.templating.TemplatingTests replaced return value with null for com/renomad/minum/templating/TemplateProcessor::processSectionInside → KILLED
154		1.1 Location : processSectionOutside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_processSectionOutside_builderEmpty(com.renomad.minum.templating.TemplateSectionTests) negated conditional → KILLED
158		1.1 Location : processSectionOutside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_processSectionOutside_builderEmpty(com.renomad.minum.templating.TemplateSectionTests) replaced return value with null for com/renomad/minum/templating/TemplateProcessor::processSectionOutside → KILLED
171		1.1 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED 2.2 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED 3.3 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests Replaced integer addition with subtraction → KILLED 4.4 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests changed conditional boundary → KILLED 5.5 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED 6.6 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests replaced boolean return with true for com/renomad/minum/templating/TemplateProcessor::justArrivedOutside → KILLED 7.7 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests Replaced integer addition with subtraction → KILLED 8.8 Location : justArrivedOutside Killed by : com.renomad.minum.templating.TemplatingTests negated conditional → KILLED
184		1.1 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) negated conditional → KILLED 2.2 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) negated conditional → KILLED 3.3 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) replaced boolean return with true for com/renomad/minum/templating/TemplateProcessor::justArrivedInside → KILLED 4.4 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) Replaced integer addition with subtraction → KILLED 5.5 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) negated conditional → KILLED 6.6 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) Replaced integer addition with subtraction → KILLED 7.7 Location : justArrivedInside Killed by : com.renomad.minum.templating.TemplateSectionTests.test_justArrivedInside(com.renomad.minum.templating.TemplateSectionTests) changed conditional boundary → KILLED

TemplateProcessor.java

Mutations

Active mutators

Tests examined